8016025: JSR 310 DateTime API Updates IV

8020418: Cleanup of -Xlint warnings in java.time
8016623: test/java/time/format/TestDateTimeTextProvider.java failing
Summary: Integration of JSR310 Date/Time API update IV
Reviewed-by: sherman
Contributed-by: scolebourne@joda.org, roger.riggs@oracle.com, masayoshi.okutsu@oracle.com, patrick.zhang@oracle.com, chand.basha@oracle.com

src/share/classes/java/time/DayOfWeek.java

@@ -61,7 +61,6 @@
  */
 package java.time;
 
-import java.time.temporal.UnsupportedTemporalTypeException;
 import static java.time.temporal.ChronoField.DAY_OF_WEEK;
 import static java.time.temporal.ChronoUnit.DAYS;
 
@@ -73,6 +72,7 @@ import java.time.temporal.TemporalAccessor;
 import java.time.temporal.TemporalAdjuster;
 import java.time.temporal.TemporalField;
 import java.time.temporal.TemporalQuery;
+import java.time.temporal.UnsupportedTemporalTypeException;
 import java.time.temporal.ValueRange;
 import java.time.temporal.WeekFields;
 import java.util.Locale;
@@ -339,7 +339,7 @@ public enum DayOfWeek implements TemporalAccessor, TemporalAdjuster {
         if (field == DAY_OF_WEEK) {
             return getValue();
         } else if (field instanceof ChronoField) {
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.getFrom(this);
     }

src/share/classes/java/time/Duration.java

@@ -459,9 +459,9 @@ public final class Duration
      */
     public static Duration between(Temporal startInclusive, Temporal endExclusive) {
         try {
-            return ofNanos(startInclusive.periodUntil(endExclusive, NANOS));
+            return ofNanos(startInclusive.until(endExclusive, NANOS));
         } catch (DateTimeException | ArithmeticException ex) {
-            long secs = startInclusive.periodUntil(endExclusive, SECONDS);
+            long secs = startInclusive.until(endExclusive, SECONDS);
             long nanos;
             try {
                 nanos = endExclusive.getLong(NANO_OF_SECOND) - startInclusive.getLong(NANO_OF_SECOND);
@@ -523,7 +523,7 @@ public final class Duration
         } else if (unit == NANOS) {
             return nanos;
         } else {
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
     }
 

src/share/classes/java/time/Instant.java

@@ -69,6 +69,7 @@ import static java.time.temporal.ChronoField.INSTANT_SECONDS;
 import static java.time.temporal.ChronoField.MICRO_OF_SECOND;
 import static java.time.temporal.ChronoField.MILLI_OF_SECOND;
 import static java.time.temporal.ChronoField.NANO_OF_SECOND;
+import static java.time.temporal.ChronoUnit.DAYS;
 import static java.time.temporal.ChronoUnit.NANOS;
 
 import java.io.DataInput;
@@ -418,8 +419,9 @@ public final class Instant
      * Checks if the specified field is supported.
      * <p>
      * This checks if this instant can be queried for the specified field.
-     * If false, then calling the {@link #range(TemporalField) range} and
-     * {@link #get(TemporalField) get} methods will throw an exception.
+     * If false, then calling the {@link #range(TemporalField) range},
+     * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
+     * methods will throw an exception.
      * <p>
      * If the field is a {@link ChronoField} then the query is implemented here.
      * The supported fields are:
@@ -447,6 +449,44 @@ public final class Instant
         return field != null && field.isSupportedBy(this);
     }
 
+    /**
+     * Checks if the specified unit is supported.
+     * <p>
+     * This checks if the specified unit can be added to, or subtracted from, this date-time.
+     * If false, then calling the {@link #plus(long, TemporalUnit)} and
+     * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
+     * <p>
+     * If the unit is a {@link ChronoUnit} then the query is implemented here.
+     * The supported units are:
+     * <ul>
+     * <li>{@code NANOS}
+     * <li>{@code MICROS}
+     * <li>{@code MILLIS}
+     * <li>{@code SECONDS}
+     * <li>{@code MINUTES}
+     * <li>{@code HOURS}
+     * <li>{@code HALF_DAYS}
+     * <li>{@code DAYS}
+     * </ul>
+     * All other {@code ChronoUnit} instances will return false.
+     * <p>
+     * If the unit is not a {@code ChronoUnit}, then the result of this method
+     * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
+     * passing {@code this} as the argument.
+     * Whether the unit is supported is determined by the unit.
+     *
+     * @param unit  the unit to check, null returns false
+     * @return true if the unit can be added/subtracted, false if not
+     */
+    @Override
+    public boolean isSupported(TemporalUnit unit) {
+        if (unit instanceof ChronoUnit) {
+            return unit.isTimeBased() || unit == DAYS;
+        }
+        return unit != null && unit.isSupportedBy(this);
+    }
+
+    //-----------------------------------------------------------------------
     /**
      * Gets the range of valid values for the specified field.
      * <p>
@@ -511,7 +551,7 @@ public final class Instant
                 case MILLI_OF_SECOND: return nanos / 1000_000;
                 case INSTANT_SECONDS: INSTANT_SECONDS.checkValidIntValue(seconds);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return range(field).checkValidIntValue(field.getFrom(this), field);
     }
@@ -548,7 +588,7 @@ public final class Instant
                 case MILLI_OF_SECOND: return nanos / 1000_000;
                 case INSTANT_SECONDS: return seconds;
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.getFrom(this);
     }
@@ -665,7 +705,7 @@ public final class Instant
                 case NANO_OF_SECOND: return (newValue != nanos ? create(seconds, (int) newValue) : this);
                 case INSTANT_SECONDS: return (newValue != seconds ? create(newValue, nanos) : this);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.adjustInto(this, newValue);
     }
@@ -807,7 +847,7 @@ public final class Instant
                 case HALF_DAYS: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY / 2));
                 case DAYS: return plusSeconds(Math.multiplyExact(amountToAdd, SECONDS_PER_DAY));
             }
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
         return unit.addTo(this, amountToAdd);
     }
@@ -1053,14 +1093,14 @@ public final class Instant
      * complete units between the two instants.
      * The {@code Temporal} passed to this method must be an {@code Instant}.
      * For example, the amount in days between two dates can be calculated
-     * using {@code startInstant.periodUntil(endInstant, SECONDS)}.
+     * using {@code startInstant.until(endInstant, SECONDS)}.
      * <p>
      * There are two equivalent ways of using this method.
      * The first is to invoke this method.
      * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
      * <pre>
      *   // these two lines are equivalent
-     *   amount = start.periodUntil(end, SECONDS);
+     *   amount = start.until(end, SECONDS);
      *   amount = SECONDS.between(start, end);
      * </pre>
      * The choice should be made based on which makes the code more readable.
@@ -1085,7 +1125,7 @@ public final class Instant
      * @throws ArithmeticException if numeric overflow occurs
      */
     @Override
-    public long periodUntil(Temporal endInstant, TemporalUnit unit) {
+    public long until(Temporal endInstant, TemporalUnit unit) {
         if (endInstant instanceof Instant == false) {
             Objects.requireNonNull(endInstant, "endInstant");
             throw new DateTimeException("Unable to calculate amount as objects are of two different types");
@@ -1103,7 +1143,7 @@ public final class Instant
                 case HALF_DAYS: return secondsUntil(end) / (12 * SECONDS_PER_HOUR);
                 case DAYS: return secondsUntil(end) / (SECONDS_PER_DAY);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
         return unit.between(this, endInstant);
     }

src/share/classes/java/time/LocalDate.java

@@ -127,7 +127,7 @@ import java.util.Objects;
  * @since 1.8
  */
 public final class LocalDate
-        implements Temporal, TemporalAdjuster, ChronoLocalDate<LocalDate>, Serializable {
+        implements Temporal, TemporalAdjuster, ChronoLocalDate, Serializable {
 
     /**
      * The minimum supported {@code LocalDate}, '-999999999-01-01'.
@@ -466,8 +466,9 @@ public final class LocalDate
      * Checks if the specified field is supported.
      * <p>
      * This checks if this date can be queried for the specified field.
-     * If false, then calling the {@link #range(TemporalField) range} and
-     * {@link #get(TemporalField) get} methods will throw an exception.
+     * If false, then calling the {@link #range(TemporalField) range},
+     * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
+     * methods will throw an exception.
      * <p>
      * If the field is a {@link ChronoField} then the query is implemented here.
      * The supported fields are:
@@ -501,6 +502,41 @@ public final class LocalDate
         return ChronoLocalDate.super.isSupported(field);
     }
 
+    /**
+     * Checks if the specified unit is supported.
+     * <p>
+     * This checks if the specified unit can be added to, or subtracted from, this date-time.
+     * If false, then calling the {@link #plus(long, TemporalUnit)} and
+     * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
+     * <p>
+     * If the unit is a {@link ChronoUnit} then the query is implemented here.
+     * The supported units are:
+     * <ul>
+     * <li>{@code DAYS}
+     * <li>{@code WEEKS}
+     * <li>{@code MONTHS}
+     * <li>{@code YEARS}
+     * <li>{@code DECADES}
+     * <li>{@code CENTURIES}
+     * <li>{@code MILLENNIA}
+     * <li>{@code ERAS}
+     * </ul>
+     * All other {@code ChronoUnit} instances will return false.
+     * <p>
+     * If the unit is not a {@code ChronoUnit}, then the result of this method
+     * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
+     * passing {@code this} as the argument.
+     * Whether the unit is supported is determined by the unit.
+     *
+     * @param unit  the unit to check, null returns false
+     * @return true if the unit can be added/subtracted, false if not
+     */
+    @Override  // override for Javadoc
+    public boolean isSupported(TemporalUnit unit) {
+        return ChronoLocalDate.super.isSupported(unit);
+    }
+
+    //-----------------------------------------------------------------------
     /**
      * Gets the range of valid values for the specified field.
      * <p>
@@ -538,7 +574,7 @@ public final class LocalDate
                 }
                 return field.range();
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.rangeRefinedBy(this);
     }
@@ -631,7 +667,7 @@ public final class LocalDate
             case YEAR: return year;
             case ERA: return (year >= 1 ? 1 : 0);
         }
-        throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+        throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
     }
 
     private long getProlepticMonth() {
@@ -988,7 +1024,7 @@ public final class LocalDate
                 case YEAR: return withYear((int) newValue);
                 case ERA: return (getLong(ERA) == newValue ? this : withYear(1 - year));
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.adjustInto(this, newValue);
     }
@@ -1187,7 +1223,7 @@ public final class LocalDate
                 case MILLENNIA: return plusYears(Math.multiplyExact(amountToAdd, 1000));
                 case ERAS: return with(ERA, Math.addExact(getLong(ERA), amountToAdd));
             }
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
         return unit.addTo(this, amountToAdd);
     }
@@ -1497,7 +1533,7 @@ public final class LocalDate
      * The result will be negative if the end is before the start.
      * The {@code Temporal} passed to this method must be a {@code LocalDate}.
      * For example, the amount in days between two dates can be calculated
-     * using {@code startDate.periodUntil(endDate, DAYS)}.
+     * using {@code startDate.until(endDate, DAYS)}.
      * <p>
      * The calculation returns a whole number, representing the number of
      * complete units between the two dates.
@@ -1509,7 +1545,7 @@ public final class LocalDate
      * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
      * <pre>
      *   // these two lines are equivalent
-     *   amount = start.periodUntil(end, MONTHS);
+     *   amount = start.until(end, MONTHS);
      *   amount = MONTHS.between(start, end);
      * </pre>
      * The choice should be made based on which makes the code more readable.
@@ -1534,7 +1570,7 @@ public final class LocalDate
      * @throws ArithmeticException if numeric overflow occurs
      */
     @Override
-    public long periodUntil(Temporal endDate, TemporalUnit unit) {
+    public long until(Temporal endDate, TemporalUnit unit) {
         Objects.requireNonNull(unit, "unit");
         if (endDate instanceof LocalDate == false) {
             Objects.requireNonNull(endDate, "endDate");
@@ -1552,7 +1588,7 @@ public final class LocalDate
                 case MILLENNIA: return monthsUntil(end) / 12000;
                 case ERAS: return end.getLong(ERA) - getLong(ERA);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
         return unit.between(this, endDate);
     }
@@ -1591,7 +1627,7 @@ public final class LocalDate
      * The second is to use {@link Period#between(LocalDate, LocalDate)}:
      * <pre>
      *   // these two lines are equivalent
-     *   period = start.periodUntil(end);
+     *   period = start.until(end);
      *   period = Period.between(start, end);
      * </pre>
      * The choice should be made based on which makes the code more readable.
@@ -1600,7 +1636,7 @@ public final class LocalDate
      * @return the period between this date and the end date, not null
      */
     @Override
-    public Period periodUntil(ChronoLocalDate<?> endDate) {
+    public Period until(ChronoLocalDate endDate) {
         LocalDate end = LocalDate.from(endDate);
         long totalMonths = end.getProlepticMonth() - this.getProlepticMonth();  // safe
         int days = end.day - this.day;
@@ -1803,7 +1839,7 @@ public final class LocalDate
      * @return the comparator value, negative if less, positive if greater
      */
     @Override  // override for Javadoc and performance
-    public int compareTo(ChronoLocalDate<?> other) {
+    public int compareTo(ChronoLocalDate other) {
         if (other instanceof LocalDate) {
             return compareTo0((LocalDate) other);
         }
@@ -1843,7 +1879,7 @@ public final class LocalDate
      * @return true if this date is after the specified date
      */
     @Override  // override for Javadoc and performance
-    public boolean isAfter(ChronoLocalDate<?> other) {
+    public boolean isAfter(ChronoLocalDate other) {
         if (other instanceof LocalDate) {
             return compareTo0((LocalDate) other) > 0;
         }
@@ -1872,7 +1908,7 @@ public final class LocalDate
      * @return true if this date is before the specified date
      */
     @Override  // override for Javadoc and performance
-    public boolean isBefore(ChronoLocalDate<?> other) {
+    public boolean isBefore(ChronoLocalDate other) {
         if (other instanceof LocalDate) {
             return compareTo0((LocalDate) other) < 0;
         }
@@ -1901,7 +1937,7 @@ public final class LocalDate
      * @return true if this date is equal to the specified date
      */
     @Override  // override for Javadoc and performance
-    public boolean isEqual(ChronoLocalDate<?> other) {
+    public boolean isEqual(ChronoLocalDate other) {
         if (other instanceof LocalDate) {
             return compareTo0((LocalDate) other) == 0;
         }

src/share/classes/java/time/LocalDateTime.java

@@ -515,8 +515,9 @@ public final class LocalDateTime
      * Checks if the specified field is supported.
      * <p>
      * This checks if this date-time can be queried for the specified field.
-     * If false, then calling the {@link #range(TemporalField) range} and
-     * {@link #get(TemporalField) get} methods will throw an exception.
+     * If false, then calling the {@link #range(TemporalField) range},
+     * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
+     * methods will throw an exception.
      * <p>
      * If the field is a {@link ChronoField} then the query is implemented here.
      * The supported fields are:
@@ -569,6 +570,48 @@ public final class LocalDateTime
         return field != null && field.isSupportedBy(this);
     }
 
+    /**
+     * Checks if the specified unit is supported.
+     * <p>
+     * This checks if the specified unit can be added to, or subtracted from, this date-time.
+     * If false, then calling the {@link #plus(long, TemporalUnit)} and
+     * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
+     * <p>
+     * If the unit is a {@link ChronoUnit} then the query is implemented here.
+     * The supported units are:
+     * <ul>
+     * <li>{@code NANOS}
+     * <li>{@code MICROS}
+     * <li>{@code MILLIS}
+     * <li>{@code SECONDS}
+     * <li>{@code MINUTES}
+     * <li>{@code HOURS}
+     * <li>{@code HALF_DAYS}
+     * <li>{@code DAYS}
+     * <li>{@code WEEKS}
+     * <li>{@code MONTHS}
+     * <li>{@code YEARS}
+     * <li>{@code DECADES}
+     * <li>{@code CENTURIES}
+     * <li>{@code MILLENNIA}
+     * <li>{@code ERAS}
+     * </ul>
+     * All other {@code ChronoUnit} instances will return false.
+     * <p>
+     * If the unit is not a {@code ChronoUnit}, then the result of this method
+     * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
+     * passing {@code this} as the argument.
+     * Whether the unit is supported is determined by the unit.
+     *
+     * @param unit  the unit to check, null returns false
+     * @return true if the unit can be added/subtracted, false if not
+     */
+    @Override  // override for Javadoc
+    public boolean isSupported(TemporalUnit unit) {
+        return ChronoLocalDateTime.super.isSupported(unit);
+    }
+
+    //-----------------------------------------------------------------------
     /**
      * Gets the range of valid values for the specified field.
      * <p>
@@ -1570,7 +1613,7 @@ public final class LocalDateTime
      * The result will be negative if the end is before the start.
      * The {@code Temporal} passed to this method must be a {@code LocalDateTime}.
      * For example, the amount in days between two date-times can be calculated
-     * using {@code startDateTime.periodUntil(endDateTime, DAYS)}.
+     * using {@code startDateTime.until(endDateTime, DAYS)}.
      * <p>
      * The calculation returns a whole number, representing the number of
      * complete units between the two date-times.
@@ -1582,7 +1625,7 @@ public final class LocalDateTime
      * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
      * <pre>
      *   // these two lines are equivalent
-     *   amount = start.periodUntil(end, MONTHS);
+     *   amount = start.until(end, MONTHS);
      *   amount = MONTHS.between(start, end);
      * </pre>
      * The choice should be made based on which makes the code more readable.
@@ -1609,18 +1652,17 @@ public final class LocalDateTime
      * @throws ArithmeticException if numeric overflow occurs
      */
     @Override
-    public long periodUntil(Temporal endDateTime, TemporalUnit unit) {
+    public long until(Temporal endDateTime, TemporalUnit unit) {
         if (endDateTime instanceof LocalDateTime == false) {
             Objects.requireNonNull(endDateTime, "endDateTime");
             throw new DateTimeException("Unable to calculate amount as objects are of two different types");
         }
         LocalDateTime end = (LocalDateTime) endDateTime;
         if (unit instanceof ChronoUnit) {
-            ChronoUnit f = (ChronoUnit) unit;
-            if (f.isTimeUnit()) {
+            if (unit.isTimeBased()) {
                 long amount = date.daysUntil(end.date);
                 if (amount == 0) {
-                    return time.periodUntil(end.time, unit);
+                    return time.until(end.time, unit);
                 }
                 long timePart = end.time.toNanoOfDay() - time.toNanoOfDay();
                 if (amount > 0) {
@@ -1630,7 +1672,7 @@ public final class LocalDateTime
                     amount++;  // safe
                     timePart -= NANOS_PER_DAY;  // safe
                 }
-                switch (f) {
+                switch ((ChronoUnit) unit) {
                     case NANOS:
                         amount = Math.multiplyExact(amount, NANOS_PER_DAY);
                         break;
@@ -1667,7 +1709,7 @@ public final class LocalDateTime
             } else if (endDate.isBefore(date) && end.time.isAfter(time)) {
                 endDate = endDate.plusDays(1);
             }
-            return date.periodUntil(endDate, unit);
+            return date.until(endDate, unit);
         }
         return unit.between(this, endDateTime);
     }

src/share/classes/java/time/LocalTime.java

@@ -470,8 +470,9 @@ public final class LocalTime
      * Checks if the specified field is supported.
      * <p>
      * This checks if this time can be queried for the specified field.
-     * If false, then calling the {@link #range(TemporalField) range} and
-     * {@link #get(TemporalField) get} methods will throw an exception.
+     * If false, then calling the {@link #range(TemporalField) range},
+     * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
+     * methods will throw an exception.
      * <p>
      * If the field is a {@link ChronoField} then the query is implemented here.
      * The supported fields are:
@@ -510,6 +511,43 @@ public final class LocalTime
         return field != null && field.isSupportedBy(this);
     }
 
+    /**
+     * Checks if the specified unit is supported.
+     * <p>
+     * This checks if the specified unit can be added to, or subtracted from, this date-time.
+     * If false, then calling the {@link #plus(long, TemporalUnit)} and
+     * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
+     * <p>
+     * If the unit is a {@link ChronoUnit} then the query is implemented here.
+     * The supported units are:
+     * <ul>
+     * <li>{@code NANOS}
+     * <li>{@code MICROS}
+     * <li>{@code MILLIS}
+     * <li>{@code SECONDS}
+     * <li>{@code MINUTES}
+     * <li>{@code HOURS}
+     * <li>{@code HALF_DAYS}
+     * </ul>
+     * All other {@code ChronoUnit} instances will return false.
+     * <p>
+     * If the unit is not a {@code ChronoUnit}, then the result of this method
+     * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
+     * passing {@code this} as the argument.
+     * Whether the unit is supported is determined by the unit.
+     *
+     * @param unit  the unit to check, null returns false
+     * @return true if the unit can be added/subtracted, false if not
+     */
+    @Override  // override for Javadoc
+    public boolean isSupported(TemporalUnit unit) {
+        if (unit instanceof ChronoUnit) {
+            return unit.isTimeBased();
+        }
+        return unit != null && unit.isSupportedBy(this);
+    }
+
+    //-----------------------------------------------------------------------
     /**
      * Gets the range of valid values for the specified field.
      * <p>
@@ -628,7 +666,7 @@ public final class LocalTime
             case CLOCK_HOUR_OF_DAY: return (hour == 0 ? 24 : hour);
             case AMPM_OF_DAY: return hour / 12;
         }
-        throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+        throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
     }
 
     //-----------------------------------------------------------------------
@@ -803,7 +841,7 @@ public final class LocalTime
                 case CLOCK_HOUR_OF_DAY: return withHour((int) (newValue == 24 ? 0 : newValue));
                 case AMPM_OF_DAY: return plusHours((newValue - (hour / 12)) * 12);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.adjustInto(this, newValue);
     }
@@ -995,8 +1033,7 @@ public final class LocalTime
     @Override
     public LocalTime plus(long amountToAdd, TemporalUnit unit) {
         if (unit instanceof ChronoUnit) {
-            ChronoUnit f = (ChronoUnit) unit;
-            switch (f) {
+            switch ((ChronoUnit) unit) {
                 case NANOS: return plusNanos(amountToAdd);
                 case MICROS: return plusNanos((amountToAdd % MICROS_PER_DAY) * 1000);
                 case MILLIS: return plusNanos((amountToAdd % MILLIS_PER_DAY) * 1000_000);
@@ -1005,7 +1042,7 @@ public final class LocalTime
                 case HOURS: return plusHours(amountToAdd);
                 case HALF_DAYS: return plusHours((amountToAdd % 2) * 12);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
         return unit.addTo(this, amountToAdd);
     }
@@ -1295,7 +1332,7 @@ public final class LocalTime
      * The result will be negative if the end is before the start.
      * The {@code Temporal} passed to this method must be a {@code LocalTime}.
      * For example, the amount in hours between two times can be calculated
-     * using {@code startTime.periodUntil(endTime, HOURS)}.
+     * using {@code startTime.until(endTime, HOURS)}.
      * <p>
      * The calculation returns a whole number, representing the number of
      * complete units between the two times.
@@ -1307,7 +1344,7 @@ public final class LocalTime
      * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
      * <pre>
      *   // these two lines are equivalent
-     *   amount = start.periodUntil(end, MINUTES);
+     *   amount = start.until(end, MINUTES);
      *   amount = MINUTES.between(start, end);
      * </pre>
      * The choice should be made based on which makes the code more readable.
@@ -1332,7 +1369,7 @@ public final class LocalTime
      * @throws ArithmeticException if numeric overflow occurs
      */
     @Override
-    public long periodUntil(Temporal endTime, TemporalUnit unit) {
+    public long until(Temporal endTime, TemporalUnit unit) {
         if (endTime instanceof LocalTime == false) {
             Objects.requireNonNull(endTime, "endTime");
             throw new DateTimeException("Unable to calculate amount as objects are of two different types");
@@ -1349,7 +1386,7 @@ public final class LocalTime
                 case HOURS: return nanosUntil / NANOS_PER_HOUR;
                 case HALF_DAYS: return nanosUntil / (12 * NANOS_PER_HOUR);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
         return unit.between(this, endTime);
     }

src/share/classes/java/time/Month.java

@@ -61,7 +61,6 @@
  */
 package java.time;
 
-import java.time.temporal.UnsupportedTemporalTypeException;
 import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
 import static java.time.temporal.ChronoUnit.MONTHS;
 
@@ -75,6 +74,7 @@ import java.time.temporal.TemporalAccessor;
 import java.time.temporal.TemporalAdjuster;
 import java.time.temporal.TemporalField;
 import java.time.temporal.TemporalQuery;
+import java.time.temporal.UnsupportedTemporalTypeException;
 import java.time.temporal.ValueRange;
 import java.util.Locale;
 
@@ -370,7 +370,7 @@ public enum Month implements TemporalAccessor, TemporalAdjuster {
         if (field == MONTH_OF_YEAR) {
             return getValue();
         } else if (field instanceof ChronoField) {
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.getFrom(this);
     }

src/share/classes/java/time/MonthDay.java

@@ -438,7 +438,7 @@ public final class MonthDay
                 case DAY_OF_MONTH: return day;
                 case MONTH_OF_YEAR: return month;
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.getFrom(this);
     }

src/share/classes/java/time/OffsetDateTime.java

@@ -65,6 +65,7 @@ import static java.time.temporal.ChronoField.EPOCH_DAY;
 import static java.time.temporal.ChronoField.INSTANT_SECONDS;
 import static java.time.temporal.ChronoField.NANO_OF_DAY;
 import static java.time.temporal.ChronoField.OFFSET_SECONDS;
+import static java.time.temporal.ChronoUnit.FOREVER;
 import static java.time.temporal.ChronoUnit.NANOS;
 
 import java.io.IOException;
@@ -137,25 +138,40 @@ public final class OffsetDateTime
     public static final OffsetDateTime MAX = LocalDateTime.MAX.atOffset(ZoneOffset.MIN);
 
     /**
-     * Comparator for two {@code OffsetDateTime} instances based solely on the instant.
+     * Gets a comparator that compares two {@code OffsetDateTime} instances
+     * based solely on the instant.
      * <p>
      * This method differs from the comparison in {@link #compareTo} in that it
      * only compares the underlying instant.
      *
+     * @return a comparator that compares in time-line order
+     *
      * @see #isAfter
      * @see #isBefore
      * @see #isEqual
      */
-    public static final Comparator<OffsetDateTime> INSTANT_COMPARATOR = new Comparator<OffsetDateTime>() {
-        @Override
-        public int compare(OffsetDateTime datetime1, OffsetDateTime datetime2) {
-            int cmp = Long.compare(datetime1.toEpochSecond(), datetime2.toEpochSecond());
-            if (cmp == 0) {
-                cmp = Long.compare(datetime1.toLocalTime().toNanoOfDay(), datetime2.toLocalTime().toNanoOfDay());
-            }
-            return cmp;
+    public static Comparator<OffsetDateTime> timeLineOrder() {
+        return OffsetDateTime::compareInstant;
+    }
+
+    /**
+     * Compares this {@code OffsetDateTime} to another date-time.
+     * The comparison is based on the instant.
+     *
+     * @param datetime1  the first date-time to compare, not null
+     * @param datetime2  the other date-time to compare to, not null
+     * @return the comparator value, negative if less, positive if greater
+     */
+    private static int compareInstant(OffsetDateTime datetime1, OffsetDateTime datetime2) {
+        if (datetime1.getOffset().equals(datetime2.getOffset())) {
+            return datetime1.toLocalDateTime().compareTo(datetime2.toLocalDateTime());
+        }
+        int cmp = Long.compare(datetime1.toEpochSecond(), datetime2.toEpochSecond());
+        if (cmp == 0) {
+            cmp = datetime1.toLocalTime().getNano() - datetime2.toLocalTime().getNano();
         }
-    };
+        return cmp;
+    }
 
     /**
      * Serialization version.
@@ -406,8 +422,9 @@ public final class OffsetDateTime
      * Checks if the specified field is supported.
      * <p>
      * This checks if this date-time can be queried for the specified field.
-     * If false, then calling the {@link #range(TemporalField) range} and
-     * {@link #get(TemporalField) get} methods will throw an exception.
+     * If false, then calling the {@link #range(TemporalField) range},
+     * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
+     * methods will throw an exception.
      * <p>
      * If the field is a {@link ChronoField} then the query is implemented here.
      * The supported fields are:
@@ -458,6 +475,51 @@ public final class OffsetDateTime
         return field instanceof ChronoField || (field != null && field.isSupportedBy(this));
     }
 
+    /**
+     * Checks if the specified unit is supported.
+     * <p>
+     * This checks if the specified unit can be added to, or subtracted from, this date-time.
+     * If false, then calling the {@link #plus(long, TemporalUnit)} and
+     * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
+     * <p>
+     * If the unit is a {@link ChronoUnit} then the query is implemented here.
+     * The supported units are:
+     * <ul>
+     * <li>{@code NANOS}
+     * <li>{@code MICROS}
+     * <li>{@code MILLIS}
+     * <li>{@code SECONDS}
+     * <li>{@code MINUTES}
+     * <li>{@code HOURS}
+     * <li>{@code HALF_DAYS}
+     * <li>{@code DAYS}
+     * <li>{@code WEEKS}
+     * <li>{@code MONTHS}
+     * <li>{@code YEARS}
+     * <li>{@code DECADES}
+     * <li>{@code CENTURIES}
+     * <li>{@code MILLENNIA}
+     * <li>{@code ERAS}
+     * </ul>
+     * All other {@code ChronoUnit} instances will return false.
+     * <p>
+     * If the unit is not a {@code ChronoUnit}, then the result of this method
+     * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
+     * passing {@code this} as the argument.
+     * Whether the unit is supported is determined by the unit.
+     *
+     * @param unit  the unit to check, null returns false
+     * @return true if the unit can be added/subtracted, false if not
+     */
+    @Override  // override for Javadoc
+    public boolean isSupported(TemporalUnit unit) {
+        if (unit instanceof ChronoUnit) {
+            return unit != FOREVER;
+        }
+        return unit != null && unit.isSupportedBy(this);
+    }
+
+    //-----------------------------------------------------------------------
     /**
      * Gets the range of valid values for the specified field.
      * <p>
@@ -1528,7 +1590,7 @@ public final class OffsetDateTime
      * The start and end points are {@code this} and the specified date-time.
      * The result will be negative if the end is before the start.
      * For example, the period in days between two date-times can be calculated
-     * using {@code startDateTime.periodUntil(endDateTime, DAYS)}.
+     * using {@code startDateTime.until(endDateTime, DAYS)}.
      * <p>
      * The {@code Temporal} passed to this method must be an {@code OffsetDateTime}.
      * If the offset differs between the two date-times, the specified
@@ -1544,7 +1606,7 @@ public final class OffsetDateTime
      * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
      * <pre>
      *   // these two lines are equivalent
-     *   amount = start.periodUntil(end, MONTHS);
+     *   amount = start.until(end, MONTHS);
      *   amount = MONTHS.between(start, end);
      * </pre>
      * The choice should be made based on which makes the code more readable.
@@ -1571,7 +1633,7 @@ public final class OffsetDateTime
      * @throws ArithmeticException if numeric overflow occurs
      */
     @Override
-    public long periodUntil(Temporal endDateTime, TemporalUnit unit) {
+    public long until(Temporal endDateTime, TemporalUnit unit) {
         if (endDateTime instanceof OffsetDateTime == false) {
             Objects.requireNonNull(endDateTime, "endDateTime");
             throw new DateTimeException("Unable to calculate amount as objects are of two different types");
@@ -1579,7 +1641,7 @@ public final class OffsetDateTime
         if (unit instanceof ChronoUnit) {
             OffsetDateTime end = (OffsetDateTime) endDateTime;
             end = end.withOffsetSameInstant(offset);
-            return dateTime.periodUntil(end.dateTime, unit);
+            return dateTime.until(end.dateTime, unit);
         }
         return unit.between(this, endDateTime);
     }
@@ -1724,15 +1786,9 @@ public final class OffsetDateTime
      */
     @Override
     public int compareTo(OffsetDateTime other) {
-        if (getOffset().equals(other.getOffset())) {
-            return toLocalDateTime().compareTo(other.toLocalDateTime());
-        }
-        int cmp = Long.compare(toEpochSecond(), other.toEpochSecond());
+        int cmp = compareInstant(this, other);
         if (cmp == 0) {
-            cmp = toLocalTime().getNano() - other.toLocalTime().getNano();
-            if (cmp == 0) {
-                cmp = toLocalDateTime().compareTo(other.toLocalDateTime());
-            }
+            cmp = toLocalDateTime().compareTo(other.toLocalDateTime());
         }
         return cmp;
     }

src/share/classes/java/time/OffsetTime.java

@@ -348,8 +348,9 @@ public final class OffsetTime
      * Checks if the specified field is supported.
      * <p>
      * This checks if this time can be queried for the specified field.
-     * If false, then calling the {@link #range(TemporalField) range} and
-     * {@link #get(TemporalField) get} methods will throw an exception.
+     * If false, then calling the {@link #range(TemporalField) range},
+     * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
+     * methods will throw an exception.
      * <p>
      * If the field is a {@link ChronoField} then the query is implemented here.
      * The supported fields are:
@@ -389,6 +390,43 @@ public final class OffsetTime
         return field != null && field.isSupportedBy(this);
     }
 
+    /**
+     * Checks if the specified unit is supported.
+     * <p>
+     * This checks if the specified unit can be added to, or subtracted from, this date-time.
+     * If false, then calling the {@link #plus(long, TemporalUnit)} and
+     * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
+     * <p>
+     * If the unit is a {@link ChronoUnit} then the query is implemented here.
+     * The supported units are:
+     * <ul>
+     * <li>{@code NANOS}
+     * <li>{@code MICROS}
+     * <li>{@code MILLIS}
+     * <li>{@code SECONDS}
+     * <li>{@code MINUTES}
+     * <li>{@code HOURS}
+     * <li>{@code HALF_DAYS}
+     * </ul>
+     * All other {@code ChronoUnit} instances will return false.
+     * <p>
+     * If the unit is not a {@code ChronoUnit}, then the result of this method
+     * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
+     * passing {@code this} as the argument.
+     * Whether the unit is supported is determined by the unit.
+     *
+     * @param unit  the unit to check, null returns false
+     * @return true if the unit can be added/subtracted, false if not
+     */
+    @Override  // override for Javadoc
+    public boolean isSupported(TemporalUnit unit) {
+        if (unit instanceof ChronoUnit) {
+            return unit.isTimeBased();
+        }
+        return unit != null && unit.isSupportedBy(this);
+    }
+
+    //-----------------------------------------------------------------------
     /**
      * Gets the range of valid values for the specified field.
      * <p>
@@ -1084,7 +1122,7 @@ public final class OffsetTime
      * The start and end points are {@code this} and the specified time.
      * The result will be negative if the end is before the start.
      * For example, the period in hours between two times can be calculated
-     * using {@code startTime.periodUntil(endTime, HOURS)}.
+     * using {@code startTime.until(endTime, HOURS)}.
      * <p>
      * The {@code Temporal} passed to this method must be an {@code OffsetTime}.
      * If the offset differs between the two times, then the specified
@@ -1100,7 +1138,7 @@ public final class OffsetTime
      * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
      * <pre>
      *   // these two lines are equivalent
-     *   amount = start.periodUntil(end, MINUTES);
+     *   amount = start.until(end, MINUTES);
      *   amount = MINUTES.between(start, end);
      * </pre>
      * The choice should be made based on which makes the code more readable.
@@ -1125,7 +1163,7 @@ public final class OffsetTime
      * @throws ArithmeticException if numeric overflow occurs
      */
     @Override
-    public long periodUntil(Temporal endTime, TemporalUnit unit) {
+    public long until(Temporal endTime, TemporalUnit unit) {
         if (endTime instanceof OffsetTime == false) {
             Objects.requireNonNull(endTime, "endTime");
             throw new DateTimeException("Unable to calculate amount as objects are of two different types");
@@ -1142,7 +1180,7 @@ public final class OffsetTime
                 case HOURS: return nanosUntil / NANOS_PER_HOUR;
                 case HALF_DAYS: return nanosUntil / (12 * NANOS_PER_HOUR);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
         return unit.between(this, endTime);
     }

src/share/classes/java/time/Period.java

@@ -139,7 +139,7 @@ public final class Period
      * The pattern for parsing.
      */
     private final static Pattern PATTERN =
-            Pattern.compile("([-+]?)P(?:([-+]?[0-9]+)Y)?(?:([-+]?[0-9]+)M)?(?:([-+]?[0-9]+)D)?", Pattern.CASE_INSENSITIVE);
+            Pattern.compile("([-+]?)P(?:([-+]?[0-9]+)Y)?(?:([-+]?[0-9]+)M)?(?:([-+]?[0-9]+)W)?(?:([-+]?[0-9]+)D)?", Pattern.CASE_INSENSITIVE);
     /**
      * The set of supported units.
      */
@@ -186,6 +186,20 @@ public final class Period
         return create(0, months, 0);
     }
 
+    /**
+     * Obtains a {@code Period} representing a number of weeks.
+     * <p>
+     * The resulting period will be day-based, with the amount of days
+     * equal to the number of weeks multiplied by 7.
+     * The years and months units will be zero.
+     *
+     * @param weeks  the number of weeks, positive or negative
+     * @return the period, with the input weeks converted to days, not null
+     */
+    public static Period ofWeeks(int weeks) {
+        return create(0, 0, Math.multiplyExact(weeks, 7));
+    }
+
     /**
      * Obtains a {@code Period} representing a number of days.
      * <p>
@@ -257,22 +271,36 @@ public final class Period
      * Obtains a {@code Period} from a text string such as {@code PnYnMnD}.
      * <p>
      * This will parse the string produced by {@code toString()} which is
-     * based on the ISO-8601 period format {@code PnYnMnD}.
+     * based on the ISO-8601 period formats {@code PnYnMnD} and {@code PnW}.
      * <p>
      * The string starts with an optional sign, denoted by the ASCII negative
      * or positive symbol. If negative, the whole period is negated.
      * The ASCII letter "P" is next in upper or lower case.
-     * There are then three sections, each consisting of a number and a suffix.
-     * At least one of the three sections must be present.
-     * The sections have suffixes in ASCII of "Y", "M" and "D" for
-     * years, months and days, accepted in upper or lower case.
+     * There are then four sections, each consisting of a number and a suffix.
+     * At least one of the four sections must be present.
+     * The sections have suffixes in ASCII of "Y", "M", "W" and "D" for
+     * years, months, weeks and days, accepted in upper or lower case.
      * The suffixes must occur in order.
      * The number part of each section must consist of ASCII digits.
      * The number may be prefixed by the ASCII negative or positive symbol.
      * The number must parse to an {@code int}.
      * <p>
      * The leading plus/minus sign, and negative values for other units are
-     * not part of the ISO-8601 standard.
+     * not part of the ISO-8601 standard. In addition, ISO-8601 does not
+     * permit mixing between the {@code PnYnMnD} and {@code PnW} formats.
+     * Any week-based input is multiplied by 7 and treated as a number of days.
+     * <p>
+     * For example, the following are valid inputs:
+     * <pre>
+     *   "P2Y"             -- Period.ofYears(2)
+     *   "P3M"             -- Period.ofMonths(3)
+     *   "P4W"             -- Period.ofWeeks(4)
+     *   "P5D"             -- Period.ofDays(5)
+     *   "P1Y2M3D"         -- Period.of(1, 2, 3)
+     *   "P1Y2M3W4D"       -- Period.of(1, 2, 25)
+     *   "P-1Y2M"          -- Period.of(-1, 2, 0)
+     *   "-P1Y2M"          -- Period.of(-1, -2, 0)
+     * </pre>
      *
      * @param text  the text to parse, not null
      * @return the parsed period, not null
@@ -285,14 +313,18 @@ public final class Period
             int negate = ("-".equals(matcher.group(1)) ? -1 : 1);
             String yearMatch = matcher.group(2);
             String monthMatch = matcher.group(3);
-            String dayMatch = matcher.group(4);
-            if (yearMatch != null || monthMatch != null || dayMatch != null) {
+            String weekMatch = matcher.group(4);
+            String dayMatch = matcher.group(5);
+            if (yearMatch != null || monthMatch != null || dayMatch != null || weekMatch != null) {
                 try {
-                    return create(parseNumber(text, yearMatch, negate),
-                            parseNumber(text, monthMatch, negate),
-                            parseNumber(text, dayMatch, negate));
+                    int years = parseNumber(text, yearMatch, negate);
+                    int months = parseNumber(text, monthMatch, negate);
+                    int weeks = parseNumber(text, weekMatch, negate);
+                    int days = parseNumber(text, dayMatch, negate);
+                    days = Math.addExact(days, Math.multiplyExact(weeks, 7));
+                    return create(years, months, days);
                 } catch (NumberFormatException ex) {
-                    throw (DateTimeParseException) new DateTimeParseException("Text cannot be parsed to a Period", text, 0).initCause(ex);
+                    throw new DateTimeParseException("Text cannot be parsed to a Period", text, 0, ex);
                 }
             }
         }
@@ -307,7 +339,7 @@ public final class Period
         try {
             return Math.multiplyExact(val, negate);
         } catch (ArithmeticException ex) {
-            throw (DateTimeParseException) new DateTimeParseException("Text cannot be parsed to a Period", text, 0).initCause(ex);
+            throw new DateTimeParseException("Text cannot be parsed to a Period", text, 0, ex);
         }
     }
 
@@ -329,10 +361,10 @@ public final class Period
      * @param startDate  the start date, inclusive, not null
      * @param endDate  the end date, exclusive, not null
      * @return the period between this date and the end date, not null
-     * @see ChronoLocalDate#periodUntil(ChronoLocalDate)
+     * @see ChronoLocalDate#until(ChronoLocalDate)
      */
     public static Period between(LocalDate startDate, LocalDate endDate) {
-        return startDate.periodUntil(endDate);
+        return startDate.until(endDate);
     }
 
     //-----------------------------------------------------------------------
@@ -386,7 +418,7 @@ public final class Period
         } else if (unit == ChronoUnit.DAYS) {
             return getDays();
         } else {
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
     }
 

src/share/classes/java/time/Year.java

@@ -64,6 +64,10 @@ package java.time;
 import static java.time.temporal.ChronoField.ERA;
 import static java.time.temporal.ChronoField.YEAR;
 import static java.time.temporal.ChronoField.YEAR_OF_ERA;
+import static java.time.temporal.ChronoUnit.CENTURIES;
+import static java.time.temporal.ChronoUnit.DECADES;
+import static java.time.temporal.ChronoUnit.ERAS;
+import static java.time.temporal.ChronoUnit.MILLENNIA;
 import static java.time.temporal.ChronoUnit.YEARS;
 
 import java.io.DataInput;
@@ -329,8 +333,9 @@ public final class Year
      * Checks if the specified field is supported.
      * <p>
      * This checks if this year can be queried for the specified field.
-     * If false, then calling the {@link #range(TemporalField) range} and
-     * {@link #get(TemporalField) get} methods will throw an exception.
+     * If false, then calling the {@link #range(TemporalField) range},
+     * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
+     * methods will throw an exception.
      * <p>
      * If the field is a {@link ChronoField} then the query is implemented here.
      * The supported fields are:
@@ -357,6 +362,41 @@ public final class Year
         return field != null && field.isSupportedBy(this);
     }
 
+    /**
+     * Checks if the specified unit is supported.
+     * <p>
+     * This checks if the specified unit can be added to, or subtracted from, this date-time.
+     * If false, then calling the {@link #plus(long, TemporalUnit)} and
+     * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
+     * <p>
+     * If the unit is a {@link ChronoUnit} then the query is implemented here.
+     * The supported units are:
+     * <ul>
+     * <li>{@code YEARS}
+     * <li>{@code DECADES}
+     * <li>{@code CENTURIES}
+     * <li>{@code MILLENNIA}
+     * <li>{@code ERAS}
+     * </ul>
+     * All other {@code ChronoUnit} instances will return false.
+     * <p>
+     * If the unit is not a {@code ChronoUnit}, then the result of this method
+     * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
+     * passing {@code this} as the argument.
+     * Whether the unit is supported is determined by the unit.
+     *
+     * @param unit  the unit to check, null returns false
+     * @return true if the unit can be added/subtracted, false if not
+     */
+    @Override
+    public boolean isSupported(TemporalUnit unit) {
+        if (unit instanceof ChronoUnit) {
+            return unit == YEARS || unit == DECADES || unit == CENTURIES || unit == MILLENNIA || unit == ERAS;
+        }
+        return unit != null && unit.isSupportedBy(this);
+    }
+
+    //-----------------------------------------------------------------------
     /**
      * Gets the range of valid values for the specified field.
      * <p>
@@ -450,7 +490,7 @@ public final class Year
                 case YEAR: return year;
                 case ERA: return (year < 1 ? 0 : 1);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.getFrom(this);
     }
@@ -575,7 +615,7 @@ public final class Year
                 case YEAR: return Year.of((int) newValue);
                 case ERA: return (getLong(ERA) == newValue ? this : Year.of(1 - year));
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.adjustInto(this, newValue);
     }
@@ -664,7 +704,7 @@ public final class Year
                 case MILLENNIA: return plusYears(Math.multiplyExact(amountToAdd, 1000));
                 case ERAS: return with(ERA, Math.addExact(getLong(ERA), amountToAdd));
             }
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
         return unit.addTo(this, amountToAdd);
     }
@@ -821,7 +861,7 @@ public final class Year
      * The result will be negative if the end is before the start.
      * The {@code Temporal} passed to this method must be a {@code Year}.
      * For example, the period in decades between two year can be calculated
-     * using {@code startYear.periodUntil(endYear, DECADES)}.
+     * using {@code startYear.until(endYear, DECADES)}.
      * <p>
      * The calculation returns a whole number, representing the number of
      * complete units between the two years.
@@ -833,7 +873,7 @@ public final class Year
      * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
      * <pre>
      *   // these two lines are equivalent
-     *   amount = start.periodUntil(end, YEARS);
+     *   amount = start.until(end, YEARS);
      *   amount = YEARS.between(start, end);
      * </pre>
      * The choice should be made based on which makes the code more readable.
@@ -858,7 +898,7 @@ public final class Year
      * @throws ArithmeticException if numeric overflow occurs
      */
     @Override
-    public long periodUntil(Temporal endYear, TemporalUnit unit) {
+    public long until(Temporal endYear, TemporalUnit unit) {
         if (endYear instanceof Year == false) {
             Objects.requireNonNull(endYear, "endYear");
             throw new DateTimeException("Unable to calculate amount as objects are of two different types");
@@ -873,7 +913,7 @@ public final class Year
                 case MILLENNIA: return yearsUntil / 1000;
                 case ERAS: return end.getLong(ERA) - getLong(ERA);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
         return unit.between(this, endYear);
     }

src/share/classes/java/time/YearMonth.java

@@ -66,7 +66,12 @@ import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
 import static java.time.temporal.ChronoField.PROLEPTIC_MONTH;
 import static java.time.temporal.ChronoField.YEAR;
 import static java.time.temporal.ChronoField.YEAR_OF_ERA;
+import static java.time.temporal.ChronoUnit.CENTURIES;
+import static java.time.temporal.ChronoUnit.DECADES;
+import static java.time.temporal.ChronoUnit.ERAS;
+import static java.time.temporal.ChronoUnit.MILLENNIA;
 import static java.time.temporal.ChronoUnit.MONTHS;
+import static java.time.temporal.ChronoUnit.YEARS;
 
 import java.io.DataInput;
 import java.io.DataOutput;
@@ -313,8 +318,9 @@ public final class YearMonth
      * Checks if the specified field is supported.
      * <p>
      * This checks if this year-month can be queried for the specified field.
-     * If false, then calling the {@link #range(TemporalField) range} and
-     * {@link #get(TemporalField) get} methods will throw an exception.
+     * If false, then calling the {@link #range(TemporalField) range},
+     * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
+     * methods will throw an exception.
      * <p>
      * If the field is a {@link ChronoField} then the query is implemented here.
      * The supported fields are:
@@ -344,6 +350,42 @@ public final class YearMonth
         return field != null && field.isSupportedBy(this);
     }
 
+    /**
+     * Checks if the specified unit is supported.
+     * <p>
+     * This checks if the specified unit can be added to, or subtracted from, this date-time.
+     * If false, then calling the {@link #plus(long, TemporalUnit)} and
+     * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
+     * <p>
+     * If the unit is a {@link ChronoUnit} then the query is implemented here.
+     * The supported units are:
+     * <ul>
+     * <li>{@code MONTHS}
+     * <li>{@code YEARS}
+     * <li>{@code DECADES}
+     * <li>{@code CENTURIES}
+     * <li>{@code MILLENNIA}
+     * <li>{@code ERAS}
+     * </ul>
+     * All other {@code ChronoUnit} instances will return false.
+     * <p>
+     * If the unit is not a {@code ChronoUnit}, then the result of this method
+     * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
+     * passing {@code this} as the argument.
+     * Whether the unit is supported is determined by the unit.
+     *
+     * @param unit  the unit to check, null returns false
+     * @return true if the unit can be added/subtracted, false if not
+     */
+    @Override
+    public boolean isSupported(TemporalUnit unit) {
+        if (unit instanceof ChronoUnit) {
+            return unit == MONTHS || unit == YEARS || unit == DECADES || unit == CENTURIES || unit == MILLENNIA || unit == ERAS;
+        }
+        return unit != null && unit.isSupportedBy(this);
+    }
+
+    //-----------------------------------------------------------------------
     /**
      * Gets the range of valid values for the specified field.
      * <p>
@@ -440,7 +482,7 @@ public final class YearMonth
                 case YEAR: return year;
                 case ERA: return (year < 1 ? 0 : 1);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.getFrom(this);
     }
@@ -639,7 +681,7 @@ public final class YearMonth
                 case YEAR: return withYear((int) newValue);
                 case ERA: return (getLong(ERA) == newValue ? this : withYear(1 - year));
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.adjustInto(this, newValue);
     }
@@ -761,7 +803,7 @@ public final class YearMonth
                 case MILLENNIA: return plusYears(Math.multiplyExact(amountToAdd, 1000));
                 case ERAS: return with(ERA, Math.addExact(getLong(ERA), amountToAdd));
             }
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
         return unit.addTo(this, amountToAdd);
     }
@@ -952,7 +994,7 @@ public final class YearMonth
      * The result will be negative if the end is before the start.
      * The {@code Temporal} passed to this method must be a {@code YearMonth}.
      * For example, the period in years between two year-months can be calculated
-     * using {@code startYearMonth.periodUntil(endYearMonth, YEARS)}.
+     * using {@code startYearMonth.until(endYearMonth, YEARS)}.
      * <p>
      * The calculation returns a whole number, representing the number of
      * complete units between the two year-months.
@@ -964,7 +1006,7 @@ public final class YearMonth
      * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
      * <pre>
      *   // these two lines are equivalent
-     *   amount = start.periodUntil(end, MONTHS);
+     *   amount = start.until(end, MONTHS);
      *   amount = MONTHS.between(start, end);
      * </pre>
      * The choice should be made based on which makes the code more readable.
@@ -989,7 +1031,7 @@ public final class YearMonth
      * @throws ArithmeticException if numeric overflow occurs
      */
     @Override
-    public long periodUntil(Temporal endYearMonth, TemporalUnit unit) {
+    public long until(Temporal endYearMonth, TemporalUnit unit) {
         if (endYearMonth instanceof YearMonth == false) {
             Objects.requireNonNull(endYearMonth, "endYearMonth");
             throw new DateTimeException("Unable to calculate amount as objects are of two different types");
@@ -1005,7 +1047,7 @@ public final class YearMonth
                 case MILLENNIA: return monthsUntil / 12000;
                 case ERAS: return end.getLong(ERA) - getLong(ERA);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
         return unit.between(this, endYearMonth);
     }

src/share/classes/java/time/ZoneId.java

@@ -400,6 +400,36 @@ public abstract class ZoneId implements Serializable {
         return of(zoneId, true);
     }
 
+    /**
+     * Obtains an instance of {@code ZoneId} wrapping an offset.
+     * <p>
+     * If the prefix is "GMT", "UTC", or "UT" a {@code ZoneId}
+     * with the prefix and the non-zero offset is returned.
+     * If the prefix is empty {@code ""} the {@code ZoneOffset} is returned.
+     *
+     * @param prefix  the time-zone ID, not null
+     * @param offset  the offset, not null
+     * @return the zone ID, not null
+     * @throws IllegalArgumentException if the prefix is not one of
+     *     "GMT", "UTC", or "UT", or ""
+     */
+    public static ZoneId ofOffset(String prefix, ZoneOffset offset) {
+        Objects.requireNonNull(prefix, "prefix");
+        Objects.requireNonNull(offset, "offset");
+        if (prefix.length() == 0) {
+            return offset;
+        }
+
+        if (!prefix.equals("GMT") && !prefix.equals("UTC") && !prefix.equals("UT")) {
+             throw new IllegalArgumentException("prefix should be GMT, UTC or UT, is: " + prefix);
+        }
+
+        if (offset.getTotalSeconds() != 0) {
+            prefix = prefix.concat(offset.getId());
+        }
+        return new ZoneRegion(prefix, offset.getRules());
+    }
+
     /**
      * Parses the ID, taking a flag to indicate whether {@code ZoneRulesException}
      * should be thrown or not, used in deserialization.
@@ -433,7 +463,7 @@ public abstract class ZoneId implements Serializable {
     private static ZoneId ofWithPrefix(String zoneId, int prefixLength, boolean checkAvailable) {
         String prefix = zoneId.substring(0, prefixLength);
         if (zoneId.length() == prefixLength) {
-            return ZoneRegion.ofPrefixedOffset(prefix, ZoneOffset.UTC);
+            return ofOffset(prefix, ZoneOffset.UTC);
         }
         if (zoneId.charAt(prefixLength) != '+' && zoneId.charAt(prefixLength) != '-') {
             return ZoneRegion.ofId(zoneId, checkAvailable);  // drop through to ZoneRulesProvider
@@ -441,9 +471,9 @@ public abstract class ZoneId implements Serializable {
         try {
             ZoneOffset offset = ZoneOffset.of(zoneId.substring(prefixLength));
             if (offset == ZoneOffset.UTC) {
-                return ZoneRegion.ofPrefixedOffset(prefix, offset);
+                return ofOffset(prefix, offset);
             }
-            return ZoneRegion.ofPrefixedOffset(prefix + offset.toString(), offset);
+            return ofOffset(prefix, offset);
         } catch (DateTimeException ex) {
             throw new DateTimeException("Invalid ID for offset-based ZoneId: " + zoneId, ex);
         }

src/share/classes/java/time/ZoneOffset.java

@@ -61,7 +61,6 @@
  */
 package java.time;
 
-import java.time.temporal.UnsupportedTemporalTypeException;
 import static java.time.LocalTime.MINUTES_PER_HOUR;
 import static java.time.LocalTime.SECONDS_PER_HOUR;
 import static java.time.LocalTime.SECONDS_PER_MINUTE;
@@ -79,6 +78,7 @@ import java.time.temporal.TemporalAccessor;
 import java.time.temporal.TemporalAdjuster;
 import java.time.temporal.TemporalField;
 import java.time.temporal.TemporalQuery;
+import java.time.temporal.UnsupportedTemporalTypeException;
 import java.time.temporal.ValueRange;
 import java.time.zone.ZoneRules;
 import java.util.Objects;
@@ -581,7 +581,7 @@ public final class ZoneOffset
         if (field == OFFSET_SECONDS) {
             return totalSeconds;
         } else if (field instanceof ChronoField) {
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return range(field).checkValidIntValue(getLong(field), field);
     }
@@ -613,7 +613,7 @@ public final class ZoneOffset
         if (field == OFFSET_SECONDS) {
             return totalSeconds;
         } else if (field instanceof ChronoField) {
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.getFrom(this);
     }

src/share/classes/java/time/ZoneRegion.java

@@ -66,7 +66,6 @@ import java.time.zone.ZoneRules;
 import java.time.zone.ZoneRulesException;
 import java.time.zone.ZoneRulesProvider;
 import java.util.Objects;
-import java.util.regex.Pattern;
 
 /**
  * A geographical region where the same time-zone rules apply.
@@ -153,19 +152,6 @@ final class ZoneRegion extends ZoneId implements Serializable {
         }
     }
 
-    /**
-     * Obtains an instance of {@code ZoneId} wrapping an offset.
-     * <p>
-     * For example, zone IDs like 'UTC', 'GMT', 'UT' and 'UTC+01:30' will be setup here.
-     *
-     * @param zoneId  the time-zone ID, not null
-     * @param offset  the offset, not null
-     * @return the zone ID, not null
-     */
-    static ZoneRegion ofPrefixedOffset(String zoneId, ZoneOffset offset) {
-        return new ZoneRegion(zoneId, offset.getRules());
-    }
-
     //-------------------------------------------------------------------------
     /**
      * Constructor.

src/share/classes/java/time/ZonedDateTime.java

@@ -642,8 +642,9 @@ public final class ZonedDateTime
      * Checks if the specified field is supported.
      * <p>
      * This checks if this date-time can be queried for the specified field.
-     * If false, then calling the {@link #range(TemporalField) range} and
-     * {@link #get(TemporalField) get} methods will throw an exception.
+     * If false, then calling the {@link #range(TemporalField) range},
+     * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
+     * methods will throw an exception.
      * <p>
      * If the field is a {@link ChronoField} then the query is implemented here.
      * The supported fields are:
@@ -694,6 +695,48 @@ public final class ZonedDateTime
         return field instanceof ChronoField || (field != null && field.isSupportedBy(this));
     }
 
+    /**
+     * Checks if the specified unit is supported.
+     * <p>
+     * This checks if the specified unit can be added to, or subtracted from, this date-time.
+     * If false, then calling the {@link #plus(long, TemporalUnit)} and
+     * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
+     * <p>
+     * If the unit is a {@link ChronoUnit} then the query is implemented here.
+     * The supported units are:
+     * <ul>
+     * <li>{@code NANOS}
+     * <li>{@code MICROS}
+     * <li>{@code MILLIS}
+     * <li>{@code SECONDS}
+     * <li>{@code MINUTES}
+     * <li>{@code HOURS}
+     * <li>{@code HALF_DAYS}
+     * <li>{@code DAYS}
+     * <li>{@code WEEKS}
+     * <li>{@code MONTHS}
+     * <li>{@code YEARS}
+     * <li>{@code DECADES}
+     * <li>{@code CENTURIES}
+     * <li>{@code MILLENNIA}
+     * <li>{@code ERAS}
+     * </ul>
+     * All other {@code ChronoUnit} instances will return false.
+     * <p>
+     * If the unit is not a {@code ChronoUnit}, then the result of this method
+     * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
+     * passing {@code this} as the argument.
+     * Whether the unit is supported is determined by the unit.
+     *
+     * @param unit  the unit to check, null returns false
+     * @return true if the unit can be added/subtracted, false if not
+     */
+    @Override  // override for Javadoc
+    public boolean isSupported(TemporalUnit unit) {
+        return ChronoZonedDateTime.super.isSupported(unit);
+    }
+
+    //-----------------------------------------------------------------------
     /**
      * Gets the range of valid values for the specified field.
      * <p>
@@ -1540,8 +1583,7 @@ public final class ZonedDateTime
     @Override
     public ZonedDateTime plus(long amountToAdd, TemporalUnit unit) {
         if (unit instanceof ChronoUnit) {
-            ChronoUnit u = (ChronoUnit) unit;
-            if (u.isDateUnit()) {
+            if (unit.isDateBased()) {
                 return resolveLocal(dateTime.plus(amountToAdd, unit));
             } else {
                 return resolveInstant(dateTime.plus(amountToAdd, unit));
@@ -1990,7 +2032,7 @@ public final class ZonedDateTime
      * The start and end points are {@code this} and the specified date-time.
      * The result will be negative if the end is before the start.
      * For example, the period in days between two date-times can be calculated
-     * using {@code startDateTime.periodUntil(endDateTime, DAYS)}.
+     * using {@code startDateTime.until(endDateTime, DAYS)}.
      * <p>
      * The {@code Temporal} passed to this method must be a {@code ZonedDateTime}.
      * If the time-zone differs between the two zoned date-times, the specified
@@ -2006,7 +2048,7 @@ public final class ZonedDateTime
      * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
      * <pre>
      *   // these two lines are equivalent
-     *   amount = start.periodUntil(end, MONTHS);
+     *   amount = start.until(end, MONTHS);
      *   amount = MONTHS.between(start, end);
      * </pre>
      * The choice should be made based on which makes the code more readable.
@@ -2047,7 +2089,7 @@ public final class ZonedDateTime
      * @throws ArithmeticException if numeric overflow occurs
      */
     @Override
-    public long periodUntil(Temporal endDateTime, TemporalUnit unit) {
+    public long until(Temporal endDateTime, TemporalUnit unit) {
         if (endDateTime instanceof ZonedDateTime == false) {
             Objects.requireNonNull(endDateTime, "endDateTime");
             throw new DateTimeException("Unable to calculate amount as objects are of two different types");
@@ -2055,11 +2097,10 @@ public final class ZonedDateTime
         if (unit instanceof ChronoUnit) {
             ZonedDateTime end = (ZonedDateTime) endDateTime;
             end = end.withZoneSameInstant(zone);
-            ChronoUnit u = (ChronoUnit) unit;
-            if (u.isDateUnit()) {
-                return dateTime.periodUntil(end.dateTime, unit);
+            if (unit.isDateBased()) {
+                return dateTime.until(end.dateTime, unit);
             } else {
-                return toOffsetDateTime().periodUntil(end.toOffsetDateTime(), unit);
+                return toOffsetDateTime().until(end.toOffsetDateTime(), unit);
             }
         }
         return unit.between(this, endDateTime);

src/share/classes/java/time/chrono/ChronoDateImpl.java

@@ -67,6 +67,8 @@ import java.time.DateTimeException;
 import java.time.temporal.ChronoUnit;
 import java.time.temporal.Temporal;
 import java.time.temporal.TemporalAdjuster;
+import java.time.temporal.TemporalAmount;
+import java.time.temporal.TemporalField;
 import java.time.temporal.TemporalUnit;
 import java.time.temporal.UnsupportedTemporalTypeException;
 import java.time.temporal.ValueRange;
@@ -96,12 +98,12 @@ import java.util.Objects;
  *        // Enumerate the list of available calendars and print today for each
  *        Set<Chronology> chronos = Chronology.getAvailableChronologies();
  *        for (Chronology chrono : chronos) {
- *            ChronoLocalDate<?> date = chrono.dateNow();
+ *            ChronoLocalDate date = chrono.dateNow();
  *            System.out.printf("   %20s: %s%n", chrono.getID(), date.toString());
  *        }
  *
  *        // Print the Hijrah date and calendar
- *        ChronoLocalDate<?> date = Chronology.of("Hijrah").dateNow();
+ *        ChronoLocalDate date = Chronology.of("Hijrah").dateNow();
  *        int day = date.get(ChronoField.DAY_OF_MONTH);
  *        int dow = date.get(ChronoField.DAY_OF_WEEK);
  *        int month = date.get(ChronoField.MONTH_OF_YEAR);
@@ -110,10 +112,10 @@ import java.util.Objects;
  *                dow, day, month, year);
 
  *        // Print today's date and the last day of the year
- *        ChronoLocalDate<?> now1 = Chronology.of("Hijrah").dateNow();
- *        ChronoLocalDate<?> first = now1.with(ChronoField.DAY_OF_MONTH, 1)
+ *        ChronoLocalDate now1 = Chronology.of("Hijrah").dateNow();
+ *        ChronoLocalDate first = now1.with(ChronoField.DAY_OF_MONTH, 1)
  *                .with(ChronoField.MONTH_OF_YEAR, 1);
- *        ChronoLocalDate<?> last = first.plus(1, ChronoUnit.YEARS)
+ *        ChronoLocalDate last = first.plus(1, ChronoUnit.YEARS)
  *                .minus(1, ChronoUnit.DAYS);
  *        System.out.printf("  Today is %s: start: %s; end: %s%n", last.getChronology().getID(),
  *                first, last);
@@ -138,22 +140,61 @@ import java.util.Objects;
  * @param <D> the ChronoLocalDate of this date-time
  * @since 1.8
  */
-abstract class ChronoDateImpl<D extends ChronoLocalDate<D>>
-        implements ChronoLocalDate<D>, Temporal, TemporalAdjuster, Serializable {
+abstract class ChronoDateImpl<D extends ChronoLocalDate>
+        implements ChronoLocalDate, Temporal, TemporalAdjuster, Serializable {
 
     /**
      * Serialization version.
      */
     private static final long serialVersionUID = 6282433883239719096L;
 
+    /**
+     * Casts the {@code Temporal} to {@code ChronoLocalDate} ensuring it bas the specified chronology.
+     *
+     * @param chrono  the chronology to check for, not null
+     * @param temporal  a date-time to cast, not null
+     * @return the date-time checked and cast to {@code ChronoLocalDate}, not null
+     * @throws ClassCastException if the date-time cannot be cast to ChronoLocalDate
+     *  or the chronology is not equal this Chronology
+     */
+    static <D extends ChronoLocalDate> D ensureValid(Chronology chrono, Temporal temporal) {
+        @SuppressWarnings("unchecked")
+        D other = (D) temporal;
+        if (chrono.equals(other.getChronology()) == false) {
+            throw new ClassCastException("Chronology mismatch, expected: " + chrono.getId() + ", actual: " + other.getChronology().getId());
+        }
+        return other;
+    }
+
+    //-----------------------------------------------------------------------
     /**
      * Creates an instance.
      */
     ChronoDateImpl() {
     }
 
+    @Override
+    @SuppressWarnings("unchecked")
+    public D with(TemporalAdjuster adjuster) {
+        return (D) ChronoLocalDate.super.with(adjuster);
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public D with(TemporalField field, long value) {
+        return (D) ChronoLocalDate.super.with(field, value);
+    }
+
+    //-----------------------------------------------------------------------
+    @Override
+    @SuppressWarnings("unchecked")
+    public D plus(TemporalAmount amount) {
+        return (D) ChronoLocalDate.super.plus(amount);
+    }
+
     //-----------------------------------------------------------------------
     @Override
+    @SuppressWarnings("unchecked")
     public D plus(long amountToAdd, TemporalUnit unit) {
         if (unit instanceof ChronoUnit) {
             ChronoUnit f = (ChronoUnit) unit;
@@ -167,9 +208,21 @@ abstract class ChronoDateImpl<D extends ChronoLocalDate<D>>
                 case MILLENNIA: return plusYears(Math.multiplyExact(amountToAdd, 1000));
                 case ERAS: return with(ERA, Math.addExact(getLong(ERA), amountToAdd));
             }
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
-        return ChronoLocalDate.super.plus(amountToAdd, unit);
+        return (D) ChronoLocalDate.super.plus(amountToAdd, unit);
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public D minus(TemporalAmount amount) {
+        return (D) ChronoLocalDate.super.minus(amount);
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public D minus(long amountToSubtract, TemporalUnit unit) {
+        return (D) ChronoLocalDate.super.minus(amountToSubtract, unit);
     }
 
     //-----------------------------------------------------------------------
@@ -254,6 +307,7 @@ abstract class ChronoDateImpl<D extends ChronoLocalDate<D>>
      * @return a date based on this one with the years subtracted, not null
      * @throws DateTimeException if the result exceeds the supported date range
      */
+    @SuppressWarnings("unchecked")
     D minusYears(long yearsToSubtract) {
         return (yearsToSubtract == Long.MIN_VALUE ? ((ChronoDateImpl<D>)plusYears(Long.MAX_VALUE)).plusYears(1) : plusYears(-yearsToSubtract));
     }
@@ -274,6 +328,7 @@ abstract class ChronoDateImpl<D extends ChronoLocalDate<D>>
      * @return a date based on this one with the months subtracted, not null
      * @throws DateTimeException if the result exceeds the supported date range
      */
+    @SuppressWarnings("unchecked")
     D minusMonths(long monthsToSubtract) {
         return (monthsToSubtract == Long.MIN_VALUE ? ((ChronoDateImpl<D>)plusMonths(Long.MAX_VALUE)).plusMonths(1) : plusMonths(-monthsToSubtract));
     }
@@ -293,6 +348,7 @@ abstract class ChronoDateImpl<D extends ChronoLocalDate<D>>
      * @return a date based on this one with the weeks subtracted, not null
      * @throws DateTimeException if the result exceeds the supported date range
      */
+    @SuppressWarnings("unchecked")
     D minusWeeks(long weeksToSubtract) {
         return (weeksToSubtract == Long.MIN_VALUE ? ((ChronoDateImpl<D>)plusWeeks(Long.MAX_VALUE)).plusWeeks(1) : plusWeeks(-weeksToSubtract));
     }
@@ -310,6 +366,7 @@ abstract class ChronoDateImpl<D extends ChronoLocalDate<D>>
      * @return a date based on this one with the days subtracted, not null
      * @throws DateTimeException if the result exceeds the supported date range
      */
+    @SuppressWarnings("unchecked")
     D minusDays(long daysToSubtract) {
         return (daysToSubtract == Long.MIN_VALUE ? ((ChronoDateImpl<D>)plusDays(Long.MAX_VALUE)).plusDays(1) : plusDays(-daysToSubtract));
     }
@@ -321,13 +378,13 @@ abstract class ChronoDateImpl<D extends ChronoLocalDate<D>>
      * @throws ArithmeticException {@inheritDoc}
      */
     @Override
-    public long periodUntil(Temporal endDateTime, TemporalUnit unit) {
+    public long until(Temporal endDateTime, TemporalUnit unit) {
         Objects.requireNonNull(endDateTime, "endDateTime");
         Objects.requireNonNull(unit, "unit");
         if (endDateTime instanceof ChronoLocalDate == false) {
             throw new DateTimeException("Unable to calculate amount as objects are of two different types");
         }
-        ChronoLocalDate<?> end = (ChronoLocalDate<?>) endDateTime;
+        ChronoLocalDate end = (ChronoLocalDate) endDateTime;
         if (getChronology().equals(end.getChronology()) == false) {
             throw new DateTimeException("Unable to calculate amount as objects have different chronologies");
         }
@@ -342,16 +399,16 @@ abstract class ChronoDateImpl<D extends ChronoLocalDate<D>>
                 case MILLENNIA: return monthsUntil(end) / 12000;
                 case ERAS: return end.getLong(ERA) - getLong(ERA);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
         return unit.between(this, endDateTime);
     }
 
-    private long daysUntil(ChronoLocalDate<?> end) {
+    private long daysUntil(ChronoLocalDate end) {
         return end.toEpochDay() - toEpochDay();  // no overflow
     }
 
-    private long monthsUntil(ChronoLocalDate<?> end) {
+    private long monthsUntil(ChronoLocalDate end) {
         ValueRange range = getChronology().range(MONTH_OF_YEAR);
         if (range.getMaximum() != 12) {
             throw new IllegalStateException("ChronoDateImpl only supports Chronologies with 12 months per year");
@@ -367,7 +424,7 @@ abstract class ChronoDateImpl<D extends ChronoLocalDate<D>>
             return true;
         }
         if (obj instanceof ChronoLocalDate) {
-            return compareTo((ChronoLocalDate<?>) obj) == 0;
+            return compareTo((ChronoLocalDate) obj) == 0;
         }
         return false;
     }

src/share/classes/java/time/chrono/ChronoLocalDate.java

@@ -242,11 +242,10 @@ import java.util.Objects;
  * Additional calendar systems may be added to the system.
  * See {@link Chronology} for more details.
  *
- * @param <D> the concrete type for the date
  * @since 1.8
  */
-public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
-        extends Temporal, TemporalAdjuster, Comparable<ChronoLocalDate<?>> {
+public interface ChronoLocalDate
+        extends Temporal, TemporalAdjuster, Comparable<ChronoLocalDate> {
 
     /**
      * Gets a comparator that compares {@code ChronoLocalDate} in
@@ -263,7 +262,7 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @see #isBefore
      * @see #isEqual
      */
-    static Comparator<ChronoLocalDate<?>> timeLineOrder() {
+    static Comparator<ChronoLocalDate> timeLineOrder() {
         return Chronology.DATE_ORDER;
     }
 
@@ -289,9 +288,9 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @throws DateTimeException if unable to convert to a {@code ChronoLocalDate}
      * @see Chronology#date(TemporalAccessor)
      */
-    static ChronoLocalDate<?> from(TemporalAccessor temporal) {
+    static ChronoLocalDate from(TemporalAccessor temporal) {
         if (temporal instanceof ChronoLocalDate) {
-            return (ChronoLocalDate<?>) temporal;
+            return (ChronoLocalDate) temporal;
         }
         Chronology chrono = temporal.query(TemporalQuery.chronology());
         if (chrono == null) {
@@ -367,6 +366,25 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
         return (isLeapYear() ? 366 : 365);
     }
 
+    /**
+     * Checks if the specified field is supported.
+     * <p>
+     * This checks if the specified field can be queried on this date.
+     * If false, then calling the {@link #range(TemporalField) range},
+     * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
+     * methods will throw an exception.
+     * <p>
+     * The set of supported fields is defined by the chronology and normally includes
+     * all {@code ChronoField} date fields.
+     * <p>
+     * If the field is not a {@code ChronoField}, then the result of this method
+     * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
+     * passing {@code this} as the argument.
+     * Whether the field is supported is determined by the field.
+     *
+     * @param field  the field to check, null returns false
+     * @return true if the field can be queried, false if not
+     */
     @Override
     default boolean isSupported(TemporalField field) {
         if (field instanceof ChronoField) {
@@ -375,6 +393,32 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
         return field != null && field.isSupportedBy(this);
     }
 
+    /**
+     * Checks if the specified unit is supported.
+     * <p>
+     * This checks if the specified unit can be added to or subtracted from this date.
+     * If false, then calling the {@link #plus(long, TemporalUnit)} and
+     * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
+     * <p>
+     * The set of supported units is defined by the chronology and normally includes
+     * all {@code ChronoUnit} date units except {@code FOREVER}.
+     * <p>
+     * If the unit is not a {@code ChronoUnit}, then the result of this method
+     * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
+     * passing {@code this} as the argument.
+     * Whether the unit is supported is determined by the unit.
+     *
+     * @param unit  the unit to check, null returns false
+     * @return true if the unit can be added/subtracted, false if not
+     */
+    @Override
+    default boolean isSupported(TemporalUnit unit) {
+        if (unit instanceof ChronoUnit) {
+            return unit.isDateBased();
+        }
+        return unit != null && unit.isSupportedBy(this);
+    }
+
     //-----------------------------------------------------------------------
     // override for covariant return type
     /**
@@ -383,8 +427,8 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @throws ArithmeticException {@inheritDoc}
      */
     @Override
-    default D with(TemporalAdjuster adjuster) {
-        return (D) getChronology().ensureChronoLocalDate(Temporal.super.with(adjuster));
+    default ChronoLocalDate with(TemporalAdjuster adjuster) {
+        return ChronoDateImpl.ensureValid(getChronology(), Temporal.super.with(adjuster));
     }
 
     /**
@@ -394,11 +438,11 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @throws ArithmeticException {@inheritDoc}
      */
     @Override
-    default D with(TemporalField field, long newValue) {
+    default ChronoLocalDate with(TemporalField field, long newValue) {
         if (field instanceof ChronoField) {
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
-        return (D) getChronology().ensureChronoLocalDate(field.adjustInto(this, newValue));
+        return ChronoDateImpl.ensureValid(getChronology(), field.adjustInto(this, newValue));
     }
 
     /**
@@ -407,8 +451,8 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @throws ArithmeticException {@inheritDoc}
      */
     @Override
-    default D plus(TemporalAmount amount) {
-        return (D) getChronology().ensureChronoLocalDate(Temporal.super.plus(amount));
+    default ChronoLocalDate plus(TemporalAmount amount) {
+        return ChronoDateImpl.ensureValid(getChronology(), Temporal.super.plus(amount));
     }
 
     /**
@@ -417,11 +461,11 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @throws ArithmeticException {@inheritDoc}
      */
     @Override
-    default D plus(long amountToAdd, TemporalUnit unit) {
+    default ChronoLocalDate plus(long amountToAdd, TemporalUnit unit) {
         if (unit instanceof ChronoUnit) {
-            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
         }
-        return (D) getChronology().ensureChronoLocalDate(unit.addTo(this, amountToAdd));
+        return ChronoDateImpl.ensureValid(getChronology(), unit.addTo(this, amountToAdd));
     }
 
     /**
@@ -430,8 +474,8 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @throws ArithmeticException {@inheritDoc}
      */
     @Override
-    default D minus(TemporalAmount amount) {
-        return (D) getChronology().ensureChronoLocalDate(Temporal.super.minus(amount));
+    default ChronoLocalDate minus(TemporalAmount amount) {
+        return ChronoDateImpl.ensureValid(getChronology(), Temporal.super.minus(amount));
     }
 
     /**
@@ -441,8 +485,8 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @throws ArithmeticException {@inheritDoc}
      */
     @Override
-    default D minus(long amountToSubtract, TemporalUnit unit) {
-        return (D) getChronology().ensureChronoLocalDate(Temporal.super.minus(amountToSubtract, unit));
+    default ChronoLocalDate minus(long amountToSubtract, TemporalUnit unit) {
+        return ChronoDateImpl.ensureValid(getChronology(), Temporal.super.minus(amountToSubtract, unit));
     }
 
     //-----------------------------------------------------------------------
@@ -522,14 +566,14 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * The calculation returns a whole number, representing the number of
      * complete units between the two dates.
      * For example, the amount in days between two dates can be calculated
-     * using {@code startDate.periodUntil(endDate, DAYS)}.
+     * using {@code startDate.until(endDate, DAYS)}.
      * <p>
      * There are two equivalent ways of using this method.
      * The first is to invoke this method.
      * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
      * <pre>
      *   // these two lines are equivalent
-     *   amount = start.periodUntil(end, MONTHS);
+     *   amount = start.until(end, MONTHS);
      *   amount = MONTHS.between(start, end);
      * </pre>
      * The choice should be made based on which makes the code more readable.
@@ -555,7 +599,7 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @throws ArithmeticException if numeric overflow occurs
      */
     @Override  // override for Javadoc
-    long periodUntil(Temporal endDate, TemporalUnit unit);
+    long until(Temporal endDate, TemporalUnit unit);
 
     /**
      * Calculates the period between this date and another date as a {@code Period}.
@@ -575,7 +619,7 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @throws DateTimeException if the period cannot be calculated
      * @throws ArithmeticException if numeric overflow occurs
      */
-    Period periodUntil(ChronoLocalDate<?> endDate);
+    Period until(ChronoLocalDate endDate);
 
     /**
      * Formats this date using the specified formatter.
@@ -606,8 +650,9 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @param localTime  the local time to use, not null
      * @return the local date-time formed from this date and the specified time, not null
      */
-    default ChronoLocalDateTime<D> atTime(LocalTime localTime) {
-        return (ChronoLocalDateTime<D>)ChronoLocalDateTimeImpl.of(this, localTime);
+    @SuppressWarnings("unchecked")
+    default ChronoLocalDateTime<?> atTime(LocalTime localTime) {
+        return ChronoLocalDateTimeImpl.of(this, localTime);
     }
 
     //-----------------------------------------------------------------------
@@ -656,7 +701,7 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @return the comparator value, negative if less, positive if greater
      */
     @Override
-    default int compareTo(ChronoLocalDate<?> other) {
+    default int compareTo(ChronoLocalDate other) {
         int cmp = Long.compare(toEpochDay(), other.toEpochDay());
         if (cmp == 0) {
             cmp = getChronology().compareTo(other.getChronology());
@@ -678,7 +723,7 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @param other  the other date to compare to, not null
      * @return true if this is after the specified date
      */
-    default boolean isAfter(ChronoLocalDate<?> other) {
+    default boolean isAfter(ChronoLocalDate other) {
         return this.toEpochDay() > other.toEpochDay();
     }
 
@@ -696,7 +741,7 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @param other  the other date to compare to, not null
      * @return true if this is before the specified date
      */
-    default boolean isBefore(ChronoLocalDate<?> other) {
+    default boolean isBefore(ChronoLocalDate other) {
         return this.toEpochDay() < other.toEpochDay();
     }
 
@@ -714,7 +759,7 @@ public interface ChronoLocalDate<D extends ChronoLocalDate<D>>
      * @param other  the other date to compare to, not null
      * @return true if the underlying date is equal to the specified date
      */
-    default boolean isEqual(ChronoLocalDate<?> other) {
+    default boolean isEqual(ChronoLocalDate other) {
         return this.toEpochDay() == other.toEpochDay();
     }
 

src/share/classes/java/time/chrono/ChronoLocalDateTime.java

@@ -63,6 +63,7 @@ package java.time.chrono;
 
 import static java.time.temporal.ChronoField.EPOCH_DAY;
 import static java.time.temporal.ChronoField.NANO_OF_DAY;
+import static java.time.temporal.ChronoUnit.FOREVER;
 import static java.time.temporal.ChronoUnit.NANOS;
 
 import java.time.DateTimeException;
@@ -73,6 +74,7 @@ import java.time.ZoneId;
 import java.time.ZoneOffset;
 import java.time.format.DateTimeFormatter;
 import java.time.temporal.ChronoField;
+import java.time.temporal.ChronoUnit;
 import java.time.temporal.Temporal;
 import java.time.temporal.TemporalAccessor;
 import java.time.temporal.TemporalAdjuster;
@@ -114,7 +116,7 @@ import java.util.Objects;
  * @param <D> the concrete type for the date of this date-time
  * @since 1.8
  */
-public interface ChronoLocalDateTime<D extends ChronoLocalDate<D>>
+public interface ChronoLocalDateTime<D extends ChronoLocalDate>
         extends Temporal, TemporalAdjuster, Comparable<ChronoLocalDateTime<?>> {
 
     /**
@@ -191,9 +193,54 @@ public interface ChronoLocalDateTime<D extends ChronoLocalDate<D>>
      */
     LocalTime toLocalTime();
 
-    @Override   // Override to provide javadoc
+    /**
+     * Checks if the specified field is supported.
+     * <p>
+     * This checks if the specified field can be queried on this date-time.
+     * If false, then calling the {@link #range(TemporalField) range},
+     * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
+     * methods will throw an exception.
+     * <p>
+     * The set of supported fields is defined by the chronology and normally includes
+     * all {@code ChronoField} date and time fields.
+     * <p>
+     * If the field is not a {@code ChronoField}, then the result of this method
+     * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
+     * passing {@code this} as the argument.
+     * Whether the field is supported is determined by the field.
+     *
+     * @param field  the field to check, null returns false
+     * @return true if the field can be queried, false if not
+     */
+    @Override
     boolean isSupported(TemporalField field);
 
+    /**
+     * Checks if the specified unit is supported.
+     * <p>
+     * This checks if the specified unit can be added to or subtracted from this date-time.
+     * If false, then calling the {@link #plus(long, TemporalUnit)} and
+     * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
+     * <p>
+     * The set of supported units is defined by the chronology and normally includes
+     * all {@code ChronoUnit} units except {@code FOREVER}.
+     * <p>
+     * If the unit is not a {@code ChronoUnit}, then the result of this method
+     * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
+     * passing {@code this} as the argument.
+     * Whether the unit is supported is determined by the unit.
+     *
+     * @param unit  the unit to check, null returns false
+     * @return true if the unit can be added/subtracted, false if not
+     */
+    @Override
+    default boolean isSupported(TemporalUnit unit) {
+        if (unit instanceof ChronoUnit) {
+            return unit != FOREVER;
+        }
+        return unit != null && unit.isSupportedBy(this);
+    }
+
     //-----------------------------------------------------------------------
     // override for covariant return type
     /**
@@ -203,7 +250,7 @@ public interface ChronoLocalDateTime<D extends ChronoLocalDate<D>>
      */
     @Override
     default ChronoLocalDateTime<D> with(TemporalAdjuster adjuster) {
-        return (ChronoLocalDateTime<D>)(toLocalDate().getChronology().ensureChronoLocalDateTime(Temporal.super.with(adjuster)));
+        return ChronoLocalDateTimeImpl.ensureValid(toLocalDate().getChronology(), Temporal.super.with(adjuster));
     }
 
     /**
@@ -221,7 +268,7 @@ public interface ChronoLocalDateTime<D extends ChronoLocalDate<D>>
      */
     @Override
     default ChronoLocalDateTime<D> plus(TemporalAmount amount) {
-        return (ChronoLocalDateTime<D>)(toLocalDate().getChronology().ensureChronoLocalDateTime(Temporal.super.plus(amount)));
+        return ChronoLocalDateTimeImpl.ensureValid(toLocalDate().getChronology(), Temporal.super.plus(amount));
     }
 
     /**
@@ -239,7 +286,7 @@ public interface ChronoLocalDateTime<D extends ChronoLocalDate<D>>
      */
     @Override
     default ChronoLocalDateTime<D> minus(TemporalAmount amount) {
-        return (ChronoLocalDateTime<D>)(toLocalDate().getChronology().ensureChronoLocalDateTime(Temporal.super.minus(amount)));
+        return ChronoLocalDateTimeImpl.ensureValid(toLocalDate().getChronology(), Temporal.super.minus(amount));
     }
 
     /**
@@ -249,7 +296,7 @@ public interface ChronoLocalDateTime<D extends ChronoLocalDate<D>>
      */
     @Override
     default ChronoLocalDateTime<D> minus(long amountToSubtract, TemporalUnit unit) {
-        return (ChronoLocalDateTime<D>)(toLocalDate().getChronology().ensureChronoLocalDateTime(Temporal.super.minus(amountToSubtract, unit)));
+        return ChronoLocalDateTimeImpl.ensureValid(toLocalDate().getChronology(), Temporal.super.minus(amountToSubtract, unit));
     }
 
     //-----------------------------------------------------------------------

src/share/classes/java/time/chrono/ChronoLocalDateTimeImpl.java

@@ -98,7 +98,7 @@ import java.util.Objects;
  * @param <D> the concrete type for the date of this date-time
  * @since 1.8
  */
-final class ChronoLocalDateTimeImpl<D extends ChronoLocalDate<D>>
+final class ChronoLocalDateTimeImpl<D extends ChronoLocalDate>
         implements  ChronoLocalDateTime<D>, Temporal, TemporalAdjuster, Serializable {
 
     /**
@@ -171,9 +171,27 @@ final class ChronoLocalDateTimeImpl<D extends ChronoLocalDate<D>>
      * @param time  the local time, not null
      * @return the local date-time, not null
      */
-    @SuppressWarnings("rawtypes")
-    static ChronoLocalDateTimeImpl<?> of(ChronoLocalDate<?> date, LocalTime time) {
-        return new ChronoLocalDateTimeImpl(date, time);
+    static <R extends ChronoLocalDate> ChronoLocalDateTimeImpl<R> of(R date, LocalTime time) {
+        return new ChronoLocalDateTimeImpl<>(date, time);
+    }
+
+    /**
+     * Casts the {@code Temporal} to {@code ChronoLocalDateTime} ensuring it bas the specified chronology.
+     *
+     * @param chrono  the chronology to check for, not null
+     * @param temporal   a date-time to cast, not null
+     * @return the date-time checked and cast to {@code ChronoLocalDateTime}, not null
+     * @throws ClassCastException if the date-time cannot be cast to ChronoLocalDateTimeImpl
+     *  or the chronology is not equal this Chronology
+     */
+    static <R extends ChronoLocalDate> ChronoLocalDateTimeImpl<R> ensureValid(Chronology chrono, Temporal temporal) {
+        @SuppressWarnings("unchecked")
+        ChronoLocalDateTimeImpl<R> other = (ChronoLocalDateTimeImpl<R>) temporal;
+        if (chrono.equals(other.toLocalDate().getChronology()) == false) {
+            throw new ClassCastException("Chronology mismatch, required: " + chrono.getId()
+                    + ", actual: " + other.toLocalDate().getChronology().getId());
+        }
+        return other;
     }
 
     /**
@@ -202,7 +220,7 @@ final class ChronoLocalDateTimeImpl<D extends ChronoLocalDate<D>>
             return this;
         }
         // Validate that the new Temporal is a ChronoLocalDate (and not something else)
-        D cd = (D) date.getChronology().ensureChronoLocalDate(newDate);
+        D cd = ChronoDateImpl.ensureValid(date.getChronology(), newDate);
         return new ChronoLocalDateTimeImpl<>(cd, newTime);
     }
 
@@ -260,13 +278,13 @@ final class ChronoLocalDateTimeImpl<D extends ChronoLocalDate<D>>
     public ChronoLocalDateTimeImpl<D> with(TemporalAdjuster adjuster) {
         if (adjuster instanceof ChronoLocalDate) {
             // The Chronology is checked in with(date,time)
-            return with((ChronoLocalDate<D>) adjuster, time);
+            return with((ChronoLocalDate) adjuster, time);
         } else if (adjuster instanceof LocalTime) {
             return with(date, (LocalTime) adjuster);
         } else if (adjuster instanceof ChronoLocalDateTimeImpl) {
-            return (ChronoLocalDateTimeImpl<D>)(date.getChronology().ensureChronoLocalDateTime((ChronoLocalDateTimeImpl<?>) adjuster));
+            return ChronoLocalDateTimeImpl.ensureValid(date.getChronology(), (ChronoLocalDateTimeImpl<?>) adjuster);
         }
-        return (ChronoLocalDateTimeImpl<D>)(date.getChronology().ensureChronoLocalDateTime((ChronoLocalDateTimeImpl<?>) adjuster.adjustInto(this)));
+        return ChronoLocalDateTimeImpl.ensureValid(date.getChronology(), (ChronoLocalDateTimeImpl<?>) adjuster.adjustInto(this));
     }
 
     @Override
@@ -279,7 +297,7 @@ final class ChronoLocalDateTimeImpl<D extends ChronoLocalDate<D>>
                 return with(date.with(field, newValue), time);
             }
         }
-        return (ChronoLocalDateTimeImpl<D>)(date.getChronology().ensureChronoLocalDateTime(field.adjustInto(this, newValue)));
+        return ChronoLocalDateTimeImpl.ensureValid(date.getChronology(), field.adjustInto(this, newValue));
     }
 
     //-----------------------------------------------------------------------
@@ -298,7 +316,7 @@ final class ChronoLocalDateTimeImpl<D extends ChronoLocalDate<D>>
             }
             return with(date.plus(amountToAdd, unit), time);
         }
-        return (ChronoLocalDateTimeImpl<D>)(date.getChronology().ensureChronoLocalDateTime(unit.addTo(this, amountToAdd)));
+        return ChronoLocalDateTimeImpl.ensureValid(date.getChronology(), unit.addTo(this, amountToAdd));
     }
 
     private ChronoLocalDateTimeImpl<D> plusDays(long days) {
@@ -322,7 +340,7 @@ final class ChronoLocalDateTimeImpl<D extends ChronoLocalDate<D>>
     }
 
     //-----------------------------------------------------------------------
-    private ChronoLocalDateTimeImpl<D> plusWithOverflow(ChronoLocalDate<?> newDate, long hours, long minutes, long seconds, long nanos) {
+    private ChronoLocalDateTimeImpl<D> plusWithOverflow(D newDate, long hours, long minutes, long seconds, long nanos) {
         // 9223372036854775808 long, 2147483648 int
         if ((hours | minutes | seconds | nanos) == 0) {
             return with(newDate, time);
@@ -351,7 +369,7 @@ final class ChronoLocalDateTimeImpl<D extends ChronoLocalDate<D>>
 
     //-----------------------------------------------------------------------
     @Override
-    public long periodUntil(Temporal endDateTime, TemporalUnit unit) {
+    public long until(Temporal endDateTime, TemporalUnit unit) {
         if (endDateTime instanceof ChronoLocalDateTime == false) {
             throw new DateTimeException("Unable to calculate amount as objects are of two different types");
         }
@@ -361,10 +379,9 @@ final class ChronoLocalDateTimeImpl<D extends ChronoLocalDate<D>>
             throw new DateTimeException("Unable to calculate amount as objects have different chronologies");
         }
         if (unit instanceof ChronoUnit) {
-            ChronoUnit f = (ChronoUnit) unit;
-            if (f.isTimeUnit()) {
+            if (unit.isTimeBased()) {
                 long amount = end.getLong(EPOCH_DAY) - date.getLong(EPOCH_DAY);
-                switch (f) {
+                switch ((ChronoUnit) unit) {
                     case NANOS: amount = Math.multiplyExact(amount, NANOS_PER_DAY); break;
                     case MICROS: amount = Math.multiplyExact(amount, MICROS_PER_DAY); break;
                     case MILLIS: amount = Math.multiplyExact(amount, MILLIS_PER_DAY); break;
@@ -373,13 +390,13 @@ final class ChronoLocalDateTimeImpl<D extends ChronoLocalDate<D>>
                     case HOURS: amount = Math.multiplyExact(amount, HOURS_PER_DAY); break;
                     case HALF_DAYS: amount = Math.multiplyExact(amount, 2); break;
                 }
-                return Math.addExact(amount, time.periodUntil(end.toLocalTime(), unit));
+                return Math.addExact(amount, time.until(end.toLocalTime(), unit));
             }
-            D endDate = end.toLocalDate();
+            ChronoLocalDate endDate = end.toLocalDate();
             if (end.toLocalTime().isBefore(time)) {
                 endDate = endDate.minus(1, ChronoUnit.DAYS);
             }
-            return date.periodUntil(endDate, unit);
+            return date.until(endDate, unit);
         }
         return unit.between(this, endDateTime);
     }
@@ -404,7 +421,7 @@ final class ChronoLocalDateTimeImpl<D extends ChronoLocalDate<D>>
     }
 
     static ChronoLocalDateTime<?> readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
-        ChronoLocalDate<?> date = (ChronoLocalDate<?>) in.readObject();
+        ChronoLocalDate date = (ChronoLocalDate) in.readObject();
         LocalTime time = (LocalTime) in.readObject();
         return date.atTime(time);
     }

src/share/classes/java/time/chrono/ChronoZonedDateTime.java

@@ -63,6 +63,7 @@ package java.time.chrono;
 
 import static java.time.temporal.ChronoField.INSTANT_SECONDS;
 import static java.time.temporal.ChronoField.OFFSET_SECONDS;
+import static java.time.temporal.ChronoUnit.FOREVER;
 import static java.time.temporal.ChronoUnit.NANOS;
 
 import java.time.DateTimeException;
@@ -73,6 +74,7 @@ import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
 import java.time.temporal.ChronoField;
+import java.time.temporal.ChronoUnit;
 import java.time.temporal.Temporal;
 import java.time.temporal.TemporalAccessor;
 import java.time.temporal.TemporalAdjuster;
@@ -115,7 +117,7 @@ import java.util.Objects;
  * @param <D> the concrete type for the date of this date-time
  * @since 1.8
  */
-public interface ChronoZonedDateTime<D extends ChronoLocalDate<D>>
+public interface ChronoZonedDateTime<D extends ChronoLocalDate>
         extends Temporal, Comparable<ChronoZonedDateTime<?>> {
 
     /**
@@ -338,9 +340,54 @@ public interface ChronoZonedDateTime<D extends ChronoLocalDate<D>>
      */
     ChronoZonedDateTime<D> withZoneSameInstant(ZoneId zone);
 
-    @Override   // Override to provide javadoc
+    /**
+     * Checks if the specified field is supported.
+     * <p>
+     * This checks if the specified field can be queried on this date-time.
+     * If false, then calling the {@link #range(TemporalField) range},
+     * {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
+     * methods will throw an exception.
+     * <p>
+     * The set of supported fields is defined by the chronology and normally includes
+     * all {@code ChronoField} fields.
+     * <p>
+     * If the field is not a {@code ChronoField}, then the result of this method
+     * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
+     * passing {@code this} as the argument.
+     * Whether the field is supported is determined by the field.
+     *
+     * @param field  the field to check, null returns false
+     * @return true if the field can be queried, false if not
+     */
+    @Override
     boolean isSupported(TemporalField field);
 
+    /**
+     * Checks if the specified unit is supported.
+     * <p>
+     * This checks if the specified unit can be added to or subtracted from this date-time.
+     * If false, then calling the {@link #plus(long, TemporalUnit)} and
+     * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
+     * <p>
+     * The set of supported units is defined by the chronology and normally includes
+     * all {@code ChronoUnit} units except {@code FOREVER}.
+     * <p>
+     * If the unit is not a {@code ChronoUnit}, then the result of this method
+     * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
+     * passing {@code this} as the argument.
+     * Whether the unit is supported is determined by the unit.
+     *
+     * @param unit  the unit to check, null returns false
+     * @return true if the unit can be added/subtracted, false if not
+     */
+    @Override
+    default boolean isSupported(TemporalUnit unit) {
+        if (unit instanceof ChronoUnit) {
+            return unit != FOREVER;
+        }
+        return unit != null && unit.isSupportedBy(this);
+    }
+
     //-----------------------------------------------------------------------
     // override for covariant return type
     /**
@@ -350,7 +397,7 @@ public interface ChronoZonedDateTime<D extends ChronoLocalDate<D>>
      */
     @Override
     default ChronoZonedDateTime<D> with(TemporalAdjuster adjuster) {
-        return (ChronoZonedDateTime<D>)(toLocalDate().getChronology().ensureChronoZonedDateTime(Temporal.super.with(adjuster)));
+        return ChronoZonedDateTimeImpl.ensureValid(toLocalDate().getChronology(), Temporal.super.with(adjuster));
     }
 
     /**
@@ -368,7 +415,7 @@ public interface ChronoZonedDateTime<D extends ChronoLocalDate<D>>
      */
     @Override
     default ChronoZonedDateTime<D> plus(TemporalAmount amount) {
-        return (ChronoZonedDateTime<D>)(toLocalDate().getChronology().ensureChronoZonedDateTime(Temporal.super.plus(amount)));
+        return ChronoZonedDateTimeImpl.ensureValid(toLocalDate().getChronology(), Temporal.super.plus(amount));
     }
 
     /**
@@ -386,7 +433,7 @@ public interface ChronoZonedDateTime<D extends ChronoLocalDate<D>>
      */
     @Override
     default ChronoZonedDateTime<D> minus(TemporalAmount amount) {
-        return (ChronoZonedDateTime<D>)(toLocalDate().getChronology().ensureChronoZonedDateTime(Temporal.super.minus(amount)));
+        return ChronoZonedDateTimeImpl.ensureValid(toLocalDate().getChronology(), Temporal.super.minus(amount));
     }
 
     /**
@@ -396,7 +443,7 @@ public interface ChronoZonedDateTime<D extends ChronoLocalDate<D>>
      */
     @Override
     default ChronoZonedDateTime<D> minus(long amountToSubtract, TemporalUnit unit) {
-        return (ChronoZonedDateTime<D>)(toLocalDate().getChronology().ensureChronoZonedDateTime(Temporal.super.minus(amountToSubtract, unit)));
+        return ChronoZonedDateTimeImpl.ensureValid(toLocalDate().getChronology(), Temporal.super.minus(amountToSubtract, unit));
     }
 
     //-----------------------------------------------------------------------

src/share/classes/java/time/chrono/ChronoZonedDateTimeImpl.java

@@ -101,7 +101,7 @@ import java.util.Objects;
  * @param <D> the concrete type for the date of this date-time
  * @since 1.8
  */
-final class ChronoZonedDateTimeImpl<D extends ChronoLocalDate<D>>
+final class ChronoZonedDateTimeImpl<D extends ChronoLocalDate>
         implements ChronoZonedDateTime<D>, Serializable {
 
     /**
@@ -131,7 +131,7 @@ final class ChronoZonedDateTimeImpl<D extends ChronoLocalDate<D>>
      * @param preferredOffset  the zone offset, null if no preference
      * @return the zoned date-time, not null
      */
-    static <R extends ChronoLocalDate<R>> ChronoZonedDateTime<R> ofBest(
+    static <R extends ChronoLocalDate> ChronoZonedDateTime<R> ofBest(
             ChronoLocalDateTimeImpl<R> localDateTime, ZoneId zone, ZoneOffset preferredOffset) {
         Objects.requireNonNull(localDateTime, "localDateTime");
         Objects.requireNonNull(zone, "zone");
@@ -167,14 +167,13 @@ final class ChronoZonedDateTimeImpl<D extends ChronoLocalDate<D>>
      * @param zone  the zone identifier, not null
      * @return the zoned date-time, not null
      */
-    @SuppressWarnings("rawtypes")
     static ChronoZonedDateTimeImpl<?> ofInstant(Chronology chrono, Instant instant, ZoneId zone) {
         ZoneRules rules = zone.getRules();
         ZoneOffset offset = rules.getOffset(instant);
         Objects.requireNonNull(offset, "offset");  // protect against bad ZoneRules
         LocalDateTime ldt = LocalDateTime.ofEpochSecond(instant.getEpochSecond(), instant.getNano(), offset);
-        ChronoLocalDateTimeImpl<?> cldt = (ChronoLocalDateTimeImpl<?>) chrono.localDateTime(ldt);
-        return new ChronoZonedDateTimeImpl(cldt, offset, zone);
+        ChronoLocalDateTimeImpl<?> cldt = (ChronoLocalDateTimeImpl<?>)chrono.localDateTime(ldt);
+        return new ChronoZonedDateTimeImpl<>(cldt, offset, zone);
     }
 
     /**
@@ -184,10 +183,30 @@ final class ChronoZonedDateTimeImpl<D extends ChronoLocalDate<D>>
      * @param zone  the time-zone to use, validated not null
      * @return the zoned date-time, validated not null
      */
+    @SuppressWarnings("unchecked")
     private ChronoZonedDateTimeImpl<D> create(Instant instant, ZoneId zone) {
         return (ChronoZonedDateTimeImpl<D>)ofInstant(toLocalDate().getChronology(), instant, zone);
     }
 
+    /**
+     * Casts the {@code Temporal} to {@code ChronoZonedDateTimeImpl} ensuring it bas the specified chronology.
+     *
+     * @param chrono  the chronology to check for, not null
+     * @param temporal  a date-time to cast, not null
+     * @return the date-time checked and cast to {@code ChronoZonedDateTimeImpl}, not null
+     * @throws ClassCastException if the date-time cannot be cast to ChronoZonedDateTimeImpl
+     *  or the chronology is not equal this Chronology
+     */
+    static <R extends ChronoLocalDate> ChronoZonedDateTimeImpl<R> ensureValid(Chronology chrono, Temporal temporal) {
+        @SuppressWarnings("unchecked")
+        ChronoZonedDateTimeImpl<R> other = (ChronoZonedDateTimeImpl<R>) temporal;
+        if (chrono.equals(other.toLocalDate().getChronology()) == false) {
+            throw new ClassCastException("Chronology mismatch, required: " + chrono.getId()
+                    + ", actual: " + other.toLocalDate().getChronology().getId());
+        }
+        return other;
+    }
+
     //-----------------------------------------------------------------------
     /**
      * Constructor.
@@ -271,7 +290,7 @@ final class ChronoZonedDateTimeImpl<D extends ChronoLocalDate<D>>
             }
             return ofBest(dateTime.with(field, newValue), zone, offset);
         }
-        return (ChronoZonedDateTime<D>)(toLocalDate().getChronology().ensureChronoZonedDateTime(field.adjustInto(this, newValue)));
+        return ChronoZonedDateTimeImpl.ensureValid(toLocalDate().getChronology(), field.adjustInto(this, newValue));
     }
 
     //-----------------------------------------------------------------------
@@ -280,12 +299,12 @@ final class ChronoZonedDateTimeImpl<D extends ChronoLocalDate<D>>
         if (unit instanceof ChronoUnit) {
             return with(dateTime.plus(amountToAdd, unit));
         }
-        return (ChronoZonedDateTime<D>)(toLocalDate().getChronology().ensureChronoZonedDateTime(unit.addTo(this, amountToAdd)));   /// TODO: Generics replacement Risk!
+        return ChronoZonedDateTimeImpl.ensureValid(toLocalDate().getChronology(), unit.addTo(this, amountToAdd));   /// TODO: Generics replacement Risk!
     }
 
     //-----------------------------------------------------------------------
     @Override
-    public long periodUntil(Temporal endDateTime, TemporalUnit unit) {
+    public long until(Temporal endDateTime, TemporalUnit unit) {
         if (endDateTime instanceof ChronoZonedDateTime == false) {
             throw new DateTimeException("Unable to calculate amount as objects are of two different types");
         }
@@ -296,7 +315,7 @@ final class ChronoZonedDateTimeImpl<D extends ChronoLocalDate<D>>
         }
         if (unit instanceof ChronoUnit) {
             end = end.withZoneSameInstant(offset);
-            return dateTime.periodUntil(end.toLocalDateTime(), unit);
+            return dateTime.until(end.toLocalDateTime(), unit);
         }
         return unit.between(this, endDateTime);
     }

src/share/classes/java/time/chrono/Era.java

@@ -238,7 +238,7 @@ public interface Era extends TemporalAccessor, TemporalAdjuster {
         if (field == ERA) {
             return getValue();
         } else if (field instanceof ChronoField) {
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.getFrom(this);
     }

src/share/classes/java/time/chrono/HijrahChronology.java

@@ -71,8 +71,10 @@ import java.time.DateTimeException;
 import java.time.Instant;
 import java.time.LocalDate;
 import java.time.ZoneId;
+import java.time.format.ResolverStyle;
 import java.time.temporal.ChronoField;
 import java.time.temporal.TemporalAccessor;
+import java.time.temporal.TemporalField;
 import java.time.temporal.ValueRange;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -115,7 +117,7 @@ import sun.util.logging.PlatformLogger;
  * <tr class="altColor">
  * <td>Hijrah-umalqura</td>
  * <td>islamic-umalqura</td>
- * <td>ca-islamic-cv-umalqura</td>
+ * <td>ca-islamic-umalqura</td>
  * <td>Islamic - Umm Al-Qura calendar of Saudi Arabia</td>
  * </tr>
  * </tbody>
@@ -126,10 +128,10 @@ import sun.util.logging.PlatformLogger;
  * <p>
  * Selecting the chronology from the locale uses {@link Chronology#ofLocale}
  * to find the Chronology based on Locale supported BCP 47 extension mechanism
- * to request a specific calendar ("ca") and variant ("cv"). For example,
+ * to request a specific calendar ("ca"). For example,
  * </p>
  * <pre>
- *      Locale locale = Locale.forLanguageTag("en-US-u-ca-islamic-cv-umalqura");
+ *      Locale locale = Locale.forLanguageTag("en-US-u-ca-islamic-umalqura");
  *      Chronology chrono = Chronology.ofLocale(locale);
  * </pre>
  *
@@ -472,11 +474,16 @@ public final class HijrahChronology extends Chronology implements Serializable {
      * @param prolepticYear  the proleptic-year
      * @param dayOfYear  the day-of-year
      * @return the Hijrah local date, not null
-     * @throws DateTimeException if unable to create the date
+     * @throws DateTimeException if the value of the year is out of range,
+     *  or if the day-of-year is invalid for the year
      */
     @Override
     public HijrahDate dateYearDay(int prolepticYear, int dayOfYear) {
-        return HijrahDate.of(this, prolepticYear, 1, 1).plusDays(dayOfYear - 1);  // TODO better
+        HijrahDate date = HijrahDate.of(this, prolepticYear, 1, 1);
+        if (dayOfYear > date.lengthOfYear()) {
+            throw new DateTimeException("Invalid dayOfYear: " + dayOfYear);
+        }
+        return date.plusDays(dayOfYear - 1);
     }
 
     /**
@@ -515,16 +522,19 @@ public final class HijrahChronology extends Chronology implements Serializable {
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public ChronoLocalDateTime<HijrahDate> localDateTime(TemporalAccessor temporal) {
         return (ChronoLocalDateTime<HijrahDate>) super.localDateTime(temporal);
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public ChronoZonedDateTime<HijrahDate> zonedDateTime(TemporalAccessor temporal) {
         return (ChronoZonedDateTime<HijrahDate>) super.zonedDateTime(temporal);
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public ChronoZonedDateTime<HijrahDate> zonedDateTime(Instant instant, ZoneId zone) {
         return (ChronoZonedDateTime<HijrahDate>) super.zonedDateTime(instant, zone);
     }
@@ -550,7 +560,7 @@ public final class HijrahChronology extends Chronology implements Serializable {
     }
 
     @Override
-    public Era eraOf(int eraValue) {
+    public HijrahEra eraOf(int eraValue) {
         switch (eraValue) {
             case 1:
                 return HijrahEra.AH;
@@ -580,6 +590,8 @@ public final class HijrahChronology extends Chronology implements Serializable {
                 case YEAR:
                 case YEAR_OF_ERA:
                     return ValueRange.of(getMinimumYear(), getMaximumYear());
+                case ERA:
+                    return ValueRange.of(1, 1);
                 default:
                     return field.range();
             }
@@ -587,6 +599,13 @@ public final class HijrahChronology extends Chronology implements Serializable {
         return field.range();
     }
 
+    //-----------------------------------------------------------------------
+    @Override  // override for return type
+    public HijrahDate resolveDate(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
+        return (HijrahDate) super.resolveDate(fieldValues, resolverStyle);
+    }
+
+    //-----------------------------------------------------------------------
     /**
      * Check the validity of a year.
      *

src/share/classes/java/time/chrono/HijrahDate.java

@@ -109,7 +109,7 @@ import java.time.temporal.ValueRange;
  */
 public final class HijrahDate
         extends ChronoDateImpl<HijrahDate>
-        implements ChronoLocalDate<HijrahDate>, Serializable {
+        implements ChronoLocalDate, Serializable {
 
     /**
      * Serialization version.
@@ -204,7 +204,7 @@ public final class HijrahDate
      * @throws DateTimeException if the current date cannot be obtained
      */
     public static HijrahDate now(Clock clock) {
-        return HijrahChronology.INSTANCE.date(LocalDate.now(clock));
+        return HijrahDate.ofEpochDay(HijrahChronology.INSTANCE, LocalDate.now(clock).toEpochDay());
     }
 
     /**
@@ -349,7 +349,7 @@ public final class HijrahDate
                 }
                 return getChronology().range(f);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.rangeRefinedBy(this);
     }
@@ -372,7 +372,7 @@ public final class HijrahDate
                 case YEAR: return prolepticYear;
                 case ERA: return getEraValue();
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.getFrom(this);
     }
@@ -393,7 +393,7 @@ public final class HijrahDate
                 case ALIGNED_DAY_OF_WEEK_IN_MONTH: return plusDays(newValue - getLong(ALIGNED_DAY_OF_WEEK_IN_MONTH));
                 case ALIGNED_DAY_OF_WEEK_IN_YEAR: return plusDays(newValue - getLong(ALIGNED_DAY_OF_WEEK_IN_YEAR));
                 case DAY_OF_MONTH: return resolvePreviousValid(prolepticYear, monthOfYear, nvalue);
-                case DAY_OF_YEAR: return resolvePreviousValid(prolepticYear, ((nvalue - 1) / 30) + 1, ((nvalue - 1) % 30) + 1);
+                case DAY_OF_YEAR: return plusDays(Math.min(nvalue, lengthOfYear()) - getDayOfYear());
                 case EPOCH_DAY: return new HijrahDate(chrono, newValue);
                 case ALIGNED_WEEK_OF_MONTH: return plusDays((newValue - getLong(ALIGNED_WEEK_OF_MONTH)) * 7);
                 case ALIGNED_WEEK_OF_YEAR: return plusDays((newValue - getLong(ALIGNED_WEEK_OF_YEAR)) * 7);
@@ -403,9 +403,9 @@ public final class HijrahDate
                 case YEAR: return resolvePreviousValid(nvalue, monthOfYear, dayOfMonth);
                 case ERA: return resolvePreviousValid(1 - prolepticYear, monthOfYear, dayOfMonth);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
-        return ChronoLocalDate.super.with(field, newValue);
+        return super.with(field, newValue);
     }
 
     private HijrahDate resolvePreviousValid(int prolepticYear, int month, int day) {
@@ -479,7 +479,7 @@ public final class HijrahDate
      * @return the day-of-year
      */
     private int getDayOfYear() {
-        return chrono.getDayOfYear(prolepticYear, monthOfYear);
+        return chrono.getDayOfYear(prolepticYear, monthOfYear) + dayOfMonth;
     }
 
     /**
@@ -575,12 +575,13 @@ public final class HijrahDate
     }
 
     @Override        // for javadoc and covariant return type
+    @SuppressWarnings("unchecked")
     public final ChronoLocalDateTime<HijrahDate> atTime(LocalTime localTime) {
-        return super.atTime(localTime);
+        return (ChronoLocalDateTime<HijrahDate>)super.atTime(localTime);
     }
 
     @Override
-    public Period periodUntil(ChronoLocalDate<?> endDate) {
+    public Period until(ChronoLocalDate endDate) {
         // TODO: untested
         HijrahDate end = getChronology().date(endDate);
         long totalMonths = (end.prolepticYear - this.prolepticYear) * 12 + (end.monthOfYear - this.monthOfYear);  // safe
@@ -622,7 +623,7 @@ public final class HijrahDate
         return this;
     }
 
-    static ChronoLocalDate<HijrahDate> readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
+    static HijrahDate readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
         HijrahChronology chrono = (HijrahChronology) in.readObject();
         int year = in.readInt();
         int month = in.readByte();

src/share/classes/java/time/chrono/IsoChronology.java

@@ -61,25 +61,16 @@
  */
 package java.time.chrono;
 
-import static java.time.temporal.ChronoField.ALIGNED_DAY_OF_WEEK_IN_MONTH;
-import static java.time.temporal.ChronoField.ALIGNED_DAY_OF_WEEK_IN_YEAR;
-import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_MONTH;
-import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_YEAR;
 import static java.time.temporal.ChronoField.DAY_OF_MONTH;
-import static java.time.temporal.ChronoField.DAY_OF_WEEK;
-import static java.time.temporal.ChronoField.DAY_OF_YEAR;
-import static java.time.temporal.ChronoField.EPOCH_DAY;
 import static java.time.temporal.ChronoField.ERA;
 import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
 import static java.time.temporal.ChronoField.PROLEPTIC_MONTH;
 import static java.time.temporal.ChronoField.YEAR;
 import static java.time.temporal.ChronoField.YEAR_OF_ERA;
-import static java.time.temporal.TemporalAdjuster.nextOrSame;
 
 import java.io.Serializable;
 import java.time.Clock;
 import java.time.DateTimeException;
-import java.time.DayOfWeek;
 import java.time.Instant;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
@@ -398,7 +389,7 @@ public final class IsoChronology extends Chronology implements Serializable {
     }
 
     @Override
-    public Era eraOf(int eraValue) {
+    public IsoEra eraOf(int eraValue) {
         return IsoEra.of(eraValue);
     }
 
@@ -421,7 +412,7 @@ public final class IsoChronology extends Chronology implements Serializable {
      * as follows.
      * <ul>
      * <li>{@code EPOCH_DAY} - If present, this is converted to a {@code LocalDate}
-     *  all other date fields are then cross-checked against the date
+     *  and all other date fields are then cross-checked against the date.
      * <li>{@code PROLEPTIC_MONTH} - If present, then it is split into the
      *  {@code YEAR} and {@code MONTH_OF_YEAR}. If the mode is strict or smart
      *  then the field is validated.
@@ -430,7 +421,7 @@ public final class IsoChronology extends Chronology implements Serializable {
      *  range is not validated, in smart and strict mode it is. The {@code ERA} is
      *  validated for range in all three modes. If only the {@code YEAR_OF_ERA} is
      *  present, and the mode is smart or lenient, then the current era (CE/AD)
-     *  is assumed. In strict mode, no ers is assumed and the {@code YEAR_OF_ERA} is
+     *  is assumed. In strict mode, no era is assumed and the {@code YEAR_OF_ERA} is
      *  left untouched. If only the {@code ERA} is present, then it is left untouched.
      * <li>{@code YEAR}, {@code MONTH_OF_YEAR} and {@code DAY_OF_MONTH} -
      *  If all three are present, then they are combined to form a {@code LocalDate}.
@@ -495,48 +486,11 @@ public final class IsoChronology extends Chronology implements Serializable {
      */
     @Override  // override for performance
     public LocalDate resolveDate(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
-        // check epoch-day before inventing era
-        if (fieldValues.containsKey(EPOCH_DAY)) {
-            return LocalDate.ofEpochDay(fieldValues.remove(EPOCH_DAY));
-        }
-
-        // fix proleptic month before inventing era
-        resolveProlepticMonth(fieldValues, resolverStyle);
-
-        // invent era if necessary to resolve year-of-era
-        resolveYearOfEra(fieldValues, resolverStyle);
-
-        // build date
-        if (fieldValues.containsKey(YEAR)) {
-            if (fieldValues.containsKey(MONTH_OF_YEAR)) {
-                if (fieldValues.containsKey(DAY_OF_MONTH)) {
-                    return resolveYMD(fieldValues, resolverStyle);
-                }
-                if (fieldValues.containsKey(ALIGNED_WEEK_OF_MONTH)) {
-                    if (fieldValues.containsKey(ALIGNED_DAY_OF_WEEK_IN_MONTH)) {
-                        return resolveYMAA(fieldValues, resolverStyle);
-                    }
-                    if (fieldValues.containsKey(DAY_OF_WEEK)) {
-                        return resolveYMAD(fieldValues, resolverStyle);
-                    }
-                }
-            }
-            if (fieldValues.containsKey(DAY_OF_YEAR)) {
-                return resolveYD(fieldValues, resolverStyle);
-            }
-            if (fieldValues.containsKey(ALIGNED_WEEK_OF_YEAR)) {
-                if (fieldValues.containsKey(ALIGNED_DAY_OF_WEEK_IN_YEAR)) {
-                    return resolveYAA(fieldValues, resolverStyle);
-                }
-                if (fieldValues.containsKey(DAY_OF_WEEK)) {
-                    return resolveYAD(fieldValues, resolverStyle);
-                }
-            }
-        }
-        return null;
+        return (LocalDate) super.resolveDate(fieldValues, resolverStyle);
     }
 
-    private void resolveProlepticMonth(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
+    @Override  // override for better proleptic algorithm
+    void resolveProlepticMonth(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
         Long pMonth = fieldValues.remove(PROLEPTIC_MONTH);
         if (pMonth != null) {
             if (resolverStyle != ResolverStyle.LENIENT) {
@@ -547,7 +501,8 @@ public final class IsoChronology extends Chronology implements Serializable {
         }
     }
 
-    private void resolveYearOfEra(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
+    @Override  // override for enhanced behaviour
+    LocalDate resolveYearOfEra(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
         Long yoeLong = fieldValues.remove(YEAR_OF_ERA);
         if (yoeLong != null) {
             if (resolverStyle != ResolverStyle.LENIENT) {
@@ -575,10 +530,14 @@ public final class IsoChronology extends Chronology implements Serializable {
             } else {
                 throw new DateTimeException("Invalid value for era: " + era);
             }
+        } else if (fieldValues.containsKey(ERA)) {
+            ERA.checkValidValue(fieldValues.get(ERA));  // always validated
         }
+        return null;
     }
 
-    private LocalDate resolveYMD(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
+    @Override  // override for performance
+    LocalDate resolveYMD(Map <TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
         int y = YEAR.checkValidIntValue(fieldValues.remove(YEAR));
         if (resolverStyle == ResolverStyle.LENIENT) {
             long months = Math.subtractExact(fieldValues.remove(MONTH_OF_YEAR), 1);
@@ -598,96 +557,6 @@ public final class IsoChronology extends Chronology implements Serializable {
         return LocalDate.of(y, moy, dom);
     }
 
-    private LocalDate resolveYD(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
-        int y = YEAR.checkValidIntValue(fieldValues.remove(YEAR));
-        if (resolverStyle == ResolverStyle.LENIENT) {
-            long days = Math.subtractExact(fieldValues.remove(DAY_OF_YEAR), 1);
-            return LocalDate.of(y, 1, 1).plusDays(days);
-        }
-        int doy = DAY_OF_YEAR.checkValidIntValue(fieldValues.remove(DAY_OF_YEAR));
-        return LocalDate.ofYearDay(y, doy);  // smart is same as strict
-    }
-
-    private LocalDate resolveYMAA(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
-        int y = YEAR.checkValidIntValue(fieldValues.remove(YEAR));
-        if (resolverStyle == ResolverStyle.LENIENT) {
-            long months = Math.subtractExact(fieldValues.remove(MONTH_OF_YEAR), 1);
-            long weeks = Math.subtractExact(fieldValues.remove(ALIGNED_WEEK_OF_MONTH), 1);
-            long days = Math.subtractExact(fieldValues.remove(ALIGNED_DAY_OF_WEEK_IN_MONTH), 1);
-            return LocalDate.of(y, 1, 1).plusMonths(months).plusWeeks(weeks).plusDays(days);
-        }
-        int moy = MONTH_OF_YEAR.checkValidIntValue(fieldValues.remove(MONTH_OF_YEAR));
-        int aw = ALIGNED_WEEK_OF_MONTH.checkValidIntValue(fieldValues.remove(ALIGNED_WEEK_OF_MONTH));
-        int ad = ALIGNED_DAY_OF_WEEK_IN_MONTH.checkValidIntValue(fieldValues.remove(ALIGNED_DAY_OF_WEEK_IN_MONTH));
-        LocalDate date = LocalDate.of(y, moy, 1).plusDays((aw - 1) * 7 + (ad - 1));
-        if (resolverStyle == ResolverStyle.STRICT && date.getMonthValue() != moy) {
-            throw new DateTimeException("Strict mode rejected resolved date as it is in a different month");
-        }
-        return date;
-    }
-
-    private LocalDate resolveYMAD(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
-        int y = YEAR.checkValidIntValue(fieldValues.remove(YEAR));
-        if (resolverStyle == ResolverStyle.LENIENT) {
-            long months = Math.subtractExact(fieldValues.remove(MONTH_OF_YEAR), 1);
-            long weeks = Math.subtractExact(fieldValues.remove(ALIGNED_WEEK_OF_MONTH), 1);
-            long dow = Math.subtractExact(fieldValues.remove(DAY_OF_WEEK), 1);
-            return resolveAligned(y, months, weeks, dow);
-        }
-        int moy = MONTH_OF_YEAR.checkValidIntValue(fieldValues.remove(MONTH_OF_YEAR));
-        int aw = ALIGNED_WEEK_OF_MONTH.checkValidIntValue(fieldValues.remove(ALIGNED_WEEK_OF_MONTH));
-        int dow = DAY_OF_WEEK.checkValidIntValue(fieldValues.remove(DAY_OF_WEEK));
-        LocalDate date = LocalDate.of(y, moy, 1).plusDays((aw - 1) * 7).with(nextOrSame(DayOfWeek.of(dow)));
-        if (resolverStyle == ResolverStyle.STRICT && date.getMonthValue() != moy) {
-            throw new DateTimeException("Strict mode rejected resolved date as it is in a different month");
-        }
-        return date;
-    }
-
-    private LocalDate resolveYAA(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
-        int y = YEAR.checkValidIntValue(fieldValues.remove(YEAR));
-        if (resolverStyle == ResolverStyle.LENIENT) {
-            long weeks = Math.subtractExact(fieldValues.remove(ALIGNED_WEEK_OF_YEAR), 1);
-            long days = Math.subtractExact(fieldValues.remove(ALIGNED_DAY_OF_WEEK_IN_YEAR), 1);
-            return LocalDate.of(y, 1, 1).plusWeeks(weeks).plusDays(days);
-        }
-        int aw = ALIGNED_WEEK_OF_YEAR.checkValidIntValue(fieldValues.remove(ALIGNED_WEEK_OF_YEAR));
-        int ad = ALIGNED_DAY_OF_WEEK_IN_YEAR.checkValidIntValue(fieldValues.remove(ALIGNED_DAY_OF_WEEK_IN_YEAR));
-        LocalDate date = LocalDate.of(y, 1, 1).plusDays((aw - 1) * 7 + (ad - 1));
-        if (resolverStyle == ResolverStyle.STRICT && date.getYear() != y) {
-            throw new DateTimeException("Strict mode rejected resolved date as it is in a different year");
-        }
-        return date;
-    }
-
-    private LocalDate resolveYAD(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
-        int y = YEAR.checkValidIntValue(fieldValues.remove(YEAR));
-        if (resolverStyle == ResolverStyle.LENIENT) {
-            long weeks = Math.subtractExact(fieldValues.remove(ALIGNED_WEEK_OF_YEAR), 1);
-            long dow = Math.subtractExact(fieldValues.remove(DAY_OF_WEEK), 1);
-            return resolveAligned(y, 0, weeks, dow);
-        }
-        int aw = ALIGNED_WEEK_OF_YEAR.checkValidIntValue(fieldValues.remove(ALIGNED_WEEK_OF_YEAR));
-        int dow = DAY_OF_WEEK.checkValidIntValue(fieldValues.remove(DAY_OF_WEEK));
-        LocalDate date = LocalDate.of(y, 1, 1).plusDays((aw - 1) * 7).with(nextOrSame(DayOfWeek.of(dow)));
-        if (resolverStyle == ResolverStyle.STRICT && date.getYear() != y) {
-            throw new DateTimeException("Strict mode rejected resolved date as it is in a different year");
-        }
-        return date;
-    }
-
-    private LocalDate resolveAligned(int y, long months, long weeks, long dow) {
-        LocalDate date = LocalDate.of(y, 1, 1).plusMonths(months).plusWeeks(weeks);
-        if (dow > 7) {
-            date = date.plusWeeks((dow - 1) / 7);
-            dow = ((dow - 1) % 7) + 1;
-        } else if (dow < 1) {
-            date = date.plusWeeks(Math.subtractExact(dow,  7) / 7);
-            dow = ((dow + 6) % 7) + 1;
-        }
-        return date.with(nextOrSame(DayOfWeek.of((int) dow)));
-    }
-
     //-----------------------------------------------------------------------
     @Override
     public ValueRange range(ChronoField field) {

src/share/classes/java/time/chrono/JapaneseChronology.java

@@ -56,6 +56,15 @@
  */
 package java.time.chrono;
 
+import static java.time.temporal.ChronoField.DAY_OF_MONTH;
+import static java.time.temporal.ChronoField.DAY_OF_YEAR;
+import static java.time.temporal.ChronoField.ERA;
+import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
+import static java.time.temporal.ChronoField.YEAR;
+import static java.time.temporal.ChronoField.YEAR_OF_ERA;
+import static java.time.temporal.ChronoUnit.DAYS;
+import static java.time.temporal.ChronoUnit.MONTHS;
+
 import java.io.Serializable;
 import java.time.Clock;
 import java.time.DateTimeException;
@@ -63,13 +72,18 @@ import java.time.Instant;
 import java.time.LocalDate;
 import java.time.Year;
 import java.time.ZoneId;
+import java.time.format.ResolverStyle;
 import java.time.temporal.ChronoField;
 import java.time.temporal.TemporalAccessor;
+import java.time.temporal.TemporalAdjuster;
+import java.time.temporal.TemporalField;
+import java.time.temporal.UnsupportedTemporalTypeException;
 import java.time.temporal.ValueRange;
 import java.util.Arrays;
 import java.util.Calendar;
 import java.util.List;
 import java.util.Locale;
+import java.util.Map;
 
 import sun.util.calendar.CalendarSystem;
 import sun.util.calendar.LocalGregorianCalendar;
@@ -82,8 +96,22 @@ import sun.util.calendar.LocalGregorianCalendar;
  * The Japanese Imperial calendar system is the same as the ISO calendar system
  * apart from the era-based year numbering.
  * <p>
- * Only Meiji (1865-04-07 - 1868-09-07) and later eras are supported.
- * Older eras are handled as an unknown era where the year-of-era is the ISO year.
+ * Japan introduced the Gregorian calendar starting with Meiji 6.
+ * Only Meiji and later eras are supported;
+ * dates before Meiji 6, January 1 are not supported.
+ * <p>
+ * The supported {@code ChronoField} instances are:
+ * <ul>
+ * <li>{@code DAY_OF_WEEK}
+ * <li>{@code DAY_OF_MONTH}
+ * <li>{@code DAY_OF_YEAR}
+ * <li>{@code EPOCH_DAY}
+ * <li>{@code MONTH_OF_YEAR}
+ * <li>{@code PROLEPTIC_MONTH}
+ * <li>{@code YEAR_OF_ERA}
+ * <li>{@code YEAR}
+ * <li>{@code ERA}
+ * </ul>
  *
  * @implSpec
  * This class is immutable and thread-safe.
@@ -91,7 +119,6 @@ import sun.util.calendar.LocalGregorianCalendar;
  * @since 1.8
  */
 public final class JapaneseChronology extends Chronology implements Serializable {
-    // TODO: definition for unknown era may break requirement that year-of-era >= 1
 
     static final LocalGregorianCalendar JCAL =
         (LocalGregorianCalendar) CalendarSystem.forName("japanese");
@@ -152,6 +179,16 @@ public final class JapaneseChronology extends Chronology implements Serializable
     /**
      * Obtains a local date in Japanese calendar system from the
      * era, year-of-era, month-of-year and day-of-month fields.
+     * <p>
+     * The Japanese month and day-of-month are the same as those in the
+     * ISO calendar system. They are not reset when the era changes.
+     * For example:
+     * <pre>
+     *  6th Jan Showa 64 = ISO 1989-01-06
+     *  7th Jan Showa 64 = ISO 1989-01-07
+     *  8th Jan Heisei 1 = ISO 1989-01-08
+     *  9th Jan Heisei 1 = ISO 1989-01-09
+     * </pre>
      *
      * @param era  the Japanese era, not null
      * @param yearOfEra  the year-of-era
@@ -172,6 +209,9 @@ public final class JapaneseChronology extends Chronology implements Serializable
     /**
      * Obtains a local date in Japanese calendar system from the
      * proleptic-year, month-of-year and day-of-month fields.
+     * <p>
+     * The Japanese proleptic year, month and day-of-month are the same as those
+     * in the ISO calendar system. They are not reset when the era changes.
      *
      * @param prolepticYear  the proleptic-year
      * @param month  the month-of-year
@@ -187,6 +227,17 @@ public final class JapaneseChronology extends Chronology implements Serializable
     /**
      * Obtains a local date in Japanese calendar system from the
      * era, year-of-era and day-of-year fields.
+     * <p>
+     * The day-of-year in this factory is expressed relative to the start of the year-of-era.
+     * This definition changes the normal meaning of day-of-year only in those years
+     * where the year-of-era is reset to one due to a change in the era.
+     * For example:
+     * <pre>
+     *  6th Jan Showa 64 = day-of-year 6
+     *  7th Jan Showa 64 = day-of-year 7
+     *  8th Jan Heisei 1 = day-of-year 1
+     *  9th Jan Heisei 1 = day-of-year 2
+     * </pre>
      *
      * @param era  the Japanese era, not null
      * @param yearOfEra  the year-of-era
@@ -203,6 +254,10 @@ public final class JapaneseChronology extends Chronology implements Serializable
     /**
      * Obtains a local date in Japanese calendar system from the
      * proleptic-year and day-of-year fields.
+     * <p>
+     * The day-of-year in this factory is expressed relative to the start of the proleptic year.
+     * The Japanese proleptic year and day-of-year are the same as those in the ISO calendar system.
+     * They are not reset when the era changes.
      *
      * @param prolepticYear  the proleptic-year
      * @param dayOfYear  the day-of-year
@@ -211,8 +266,7 @@ public final class JapaneseChronology extends Chronology implements Serializable
      */
     @Override
     public JapaneseDate dateYearDay(int prolepticYear, int dayOfYear) {
-        LocalDate date = LocalDate.ofYearDay(prolepticYear, dayOfYear);
-        return date(prolepticYear, date.getMonthValue(), date.getDayOfMonth());
+        return new JapaneseDate(LocalDate.ofYearDay(prolepticYear, dayOfYear));
     }
 
     /**
@@ -290,15 +344,6 @@ public final class JapaneseChronology extends Chronology implements Serializable
             throw new ClassCastException("Era must be JapaneseEra");
         }
 
-        if (era == JapaneseEra.SEIREKI) {
-            JapaneseEra nextEra = JapaneseEra.values()[1];
-            int nextEraYear = nextEra.getPrivateEra().getSinceDate().getYear();
-            if (yearOfEra >= nextEraYear || yearOfEra < Year.MIN_VALUE) {
-                throw new DateTimeException("Invalid yearOfEra value");
-            }
-            return yearOfEra;
-        }
-
         JapaneseEra jera = (JapaneseEra) era;
         int gregorianYear = jera.getPrivateEra().getSinceDate().getYear() + yearOfEra - 1;
         if (yearOfEra == 1) {
@@ -320,14 +365,13 @@ public final class JapaneseChronology extends Chronology implements Serializable
      * See the description of each Era for the numeric values of:
      * {@link JapaneseEra#HEISEI}, {@link JapaneseEra#SHOWA},{@link JapaneseEra#TAISHO},
      * {@link JapaneseEra#MEIJI}), only Meiji and later eras are supported.
-     * Prior to Meiji {@link JapaneseEra#SEIREKI} is used.
      *
      * @param eraValue  the era value
      * @return the Japanese {@code Era} for the given numeric era value
      * @throws DateTimeException if {@code eraValue} is invalid
      */
     @Override
-    public Era eraOf(int eraValue) {
+    public JapaneseEra eraOf(int eraValue) {
         return JapaneseEra.of(eraValue);
     }
 
@@ -346,49 +390,117 @@ public final class JapaneseChronology extends Chronology implements Serializable
     @Override
     public ValueRange range(ChronoField field) {
         switch (field) {
-            case YEAR:
-            case DAY_OF_MONTH:
-            case DAY_OF_WEEK:
-            case MICRO_OF_DAY:
-            case MICRO_OF_SECOND:
-            case HOUR_OF_DAY:
-            case HOUR_OF_AMPM:
-            case MINUTE_OF_DAY:
-            case MINUTE_OF_HOUR:
-            case SECOND_OF_DAY:
-            case SECOND_OF_MINUTE:
-            case MILLI_OF_DAY:
-            case MILLI_OF_SECOND:
-            case NANO_OF_DAY:
-            case NANO_OF_SECOND:
-            case CLOCK_HOUR_OF_DAY:
-            case CLOCK_HOUR_OF_AMPM:
-            case EPOCH_DAY:
-            case PROLEPTIC_MONTH:
-            case MONTH_OF_YEAR:
-                return field.range();
-            case ERA:
-                return ValueRange.of(JapaneseEra.SEIREKI.getValue(),
-                                     getCurrentEra().getValue());
-        }
-        Calendar jcal = Calendar.getInstance(LOCALE);
-        int fieldIndex;
-        switch (field) {
+            case ALIGNED_DAY_OF_WEEK_IN_MONTH:
+            case ALIGNED_DAY_OF_WEEK_IN_YEAR:
+            case ALIGNED_WEEK_OF_MONTH:
+            case ALIGNED_WEEK_OF_YEAR:
+                throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
             case YEAR_OF_ERA: {
+                Calendar jcal = Calendar.getInstance(LOCALE);
                 int startYear = getCurrentEra().getPrivateEra().getSinceDate().getYear();
-                return ValueRange.of(Year.MIN_VALUE, jcal.getGreatestMinimum(Calendar.YEAR),
+                return ValueRange.of(1, jcal.getGreatestMinimum(Calendar.YEAR),
                         jcal.getLeastMaximum(Calendar.YEAR) + 1, // +1 due to the different definitions
                         Year.MAX_VALUE - startYear);
             }
-            case DAY_OF_YEAR:
-                fieldIndex = Calendar.DAY_OF_YEAR;
-                break;
+            case DAY_OF_YEAR: {
+                Calendar jcal = Calendar.getInstance(LOCALE);
+                int fieldIndex = Calendar.DAY_OF_YEAR;
+                return ValueRange.of(jcal.getMinimum(fieldIndex), jcal.getGreatestMinimum(fieldIndex),
+                        jcal.getLeastMaximum(fieldIndex), jcal.getMaximum(fieldIndex));
+            }
+            case YEAR:
+                return ValueRange.of(JapaneseDate.MEIJI_6_ISODATE.getYear(), Year.MAX_VALUE);
+            case ERA:
+                return ValueRange.of(JapaneseEra.MEIJI.getValue(), getCurrentEra().getValue());
             default:
-                 // TODO: review the remaining fields
-                throw new UnsupportedOperationException("Unimplementable field: " + field);
+                return field.range();
+        }
+    }
+
+    //-----------------------------------------------------------------------
+    @Override  // override for return type
+    public JapaneseDate resolveDate(Map <TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
+        return (JapaneseDate) super.resolveDate(fieldValues, resolverStyle);
+    }
+
+    @Override  // override for special Japanese behavior
+    ChronoLocalDate resolveYearOfEra(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
+        // validate era and year-of-era
+        Long eraLong = fieldValues.get(ERA);
+        JapaneseEra era = null;
+        if (eraLong != null) {
+            era = eraOf(range(ERA).checkValidIntValue(eraLong, ERA));  // always validated
+        }
+        Long yoeLong = fieldValues.get(YEAR_OF_ERA);
+        int yoe = 0;
+        if (yoeLong != null) {
+            yoe = range(YEAR_OF_ERA).checkValidIntValue(yoeLong, YEAR_OF_ERA);  // always validated
+        }
+        // if only year-of-era and no year then invent era unless strict
+        if (era == null && yoeLong != null && fieldValues.containsKey(YEAR) == false && resolverStyle != ResolverStyle.STRICT) {
+            era = JapaneseEra.values()[JapaneseEra.values().length - 1];
+        }
+        // if both present, then try to create date
+        if (yoeLong != null && era != null) {
+            if (fieldValues.containsKey(MONTH_OF_YEAR)) {
+                if (fieldValues.containsKey(DAY_OF_MONTH)) {
+                    return resolveYMD(era, yoe, fieldValues, resolverStyle);
+                }
+            }
+            if (fieldValues.containsKey(DAY_OF_YEAR)) {
+                return resolveYD(era, yoe, fieldValues, resolverStyle);
+            }
+        }
+        return null;
+    }
+
+    private int prolepticYearLenient(JapaneseEra era, int yearOfEra) {
+        return era.getPrivateEra().getSinceDate().getYear() + yearOfEra - 1;
+    }
+
+     private ChronoLocalDate resolveYMD(JapaneseEra era, int yoe, Map<TemporalField,Long> fieldValues, ResolverStyle resolverStyle) {
+         fieldValues.remove(ERA);
+         fieldValues.remove(YEAR_OF_ERA);
+         if (resolverStyle == ResolverStyle.LENIENT) {
+             int y = prolepticYearLenient(era, yoe);
+             long months = Math.subtractExact(fieldValues.remove(MONTH_OF_YEAR), 1);
+             long days = Math.subtractExact(fieldValues.remove(DAY_OF_MONTH), 1);
+             return date(y, 1, 1).plus(months, MONTHS).plus(days, DAYS);
+         }
+         int moy = range(MONTH_OF_YEAR).checkValidIntValue(fieldValues.remove(MONTH_OF_YEAR), MONTH_OF_YEAR);
+         int dom = range(DAY_OF_MONTH).checkValidIntValue(fieldValues.remove(DAY_OF_MONTH), DAY_OF_MONTH);
+         if (resolverStyle == ResolverStyle.SMART) {  // previous valid
+             if (yoe < 1) {
+                 throw new DateTimeException("Invalid YearOfEra: " + yoe);
+             }
+             int y = prolepticYearLenient(era, yoe);
+             JapaneseDate result;
+             try {
+                 result = date(y, moy, dom);
+             } catch (DateTimeException ex) {
+                 result = date(y, moy, 1).with(TemporalAdjuster.lastDayOfMonth());
+             }
+             // handle the era being changed
+             // only allow if the new date is in the same Jan-Dec as the era change
+             // determine by ensuring either original yoe or result yoe is 1
+             if (result.getEra() != era && result.get(YEAR_OF_ERA) > 1 && yoe > 1) {
+                 throw new DateTimeException("Invalid YearOfEra for Era: " + era + " " + yoe);
+             }
+             return result;
+         }
+         return date(era, yoe, moy, dom);
+     }
+
+    private ChronoLocalDate resolveYD(JapaneseEra era, int yoe, Map <TemporalField,Long> fieldValues, ResolverStyle resolverStyle) {
+        fieldValues.remove(ERA);
+        fieldValues.remove(YEAR_OF_ERA);
+        if (resolverStyle == ResolverStyle.LENIENT) {
+            int y = prolepticYearLenient(era, yoe);
+            long days = Math.subtractExact(fieldValues.remove(DAY_OF_YEAR), 1);
+            return dateYearDay(y, 1).plus(days, DAYS);
         }
-        return ValueRange.of(jcal.getMinimum(fieldIndex), jcal.getGreatestMinimum(fieldIndex),
-                jcal.getLeastMaximum(fieldIndex), jcal.getMaximum(fieldIndex));
+        int doy = range(DAY_OF_YEAR).checkValidIntValue(fieldValues.remove(DAY_OF_YEAR), DAY_OF_YEAR);
+        return dateYearDay(era, yoe, doy);  // smart is same as strict
     }
 
 }

src/share/classes/java/time/chrono/JapaneseDate.java

@@ -56,9 +56,15 @@
  */
 package java.time.chrono;
 
+import static java.time.temporal.ChronoField.ALIGNED_DAY_OF_WEEK_IN_MONTH;
+import static java.time.temporal.ChronoField.ALIGNED_DAY_OF_WEEK_IN_YEAR;
+import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_MONTH;
+import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_YEAR;
 import static java.time.temporal.ChronoField.DAY_OF_MONTH;
+import static java.time.temporal.ChronoField.DAY_OF_YEAR;
 import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
 import static java.time.temporal.ChronoField.YEAR;
+import static java.time.temporal.ChronoField.YEAR_OF_ERA;
 
 import java.io.DataInput;
 import java.io.DataOutput;
@@ -96,6 +102,10 @@ import sun.util.calendar.LocalGregorianCalendar;
  * apart from the era-based year numbering. The proleptic-year is defined to be
  * equal to the ISO proleptic-year.
  * <p>
+ * Japan introduced the Gregorian calendar starting with Meiji 6.
+ * Only Meiji and later eras are supported;
+ * dates before Meiji 6, January 1 are not supported.
+ * <p>
  * For example, the Japanese year "Heisei 24" corresponds to ISO year "2012".<br>
  * Calling {@code japaneseDate.get(YEAR_OF_ERA)} will return 24.<br>
  * Calling {@code japaneseDate.get(YEAR)} will return 2012.<br>
@@ -109,7 +119,7 @@ import sun.util.calendar.LocalGregorianCalendar;
  */
 public final class JapaneseDate
         extends ChronoDateImpl<JapaneseDate>
-        implements ChronoLocalDate<JapaneseDate>, Serializable {
+        implements ChronoLocalDate, Serializable {
 
     /**
      * Serialization version.
@@ -129,6 +139,11 @@ public final class JapaneseDate
      */
     private transient int yearOfEra;
 
+    /**
+     * The first day supported by the JapaneseChronology is Meiji 6, January 1st.
+     */
+    final static LocalDate MEIJI_6_ISODATE = LocalDate.of(1873, 1, 1);
+
     //-----------------------------------------------------------------------
     /**
      * Obtains the current {@code JapaneseDate} from the system clock in the default time-zone.
@@ -173,7 +188,7 @@ public final class JapaneseDate
      * @throws DateTimeException if the current date cannot be obtained
      */
     public static JapaneseDate now(Clock clock) {
-        return JapaneseChronology.INSTANCE.date(LocalDate.now(clock));
+        return new JapaneseDate(LocalDate.now(clock));
     }
 
     /**
@@ -182,6 +197,16 @@ public final class JapaneseDate
      * <p>
      * This returns a {@code JapaneseDate} with the specified fields.
      * The day must be valid for the year and month, otherwise an exception will be thrown.
+     * <p>
+     * The Japanese month and day-of-month are the same as those in the
+     * ISO calendar system. They are not reset when the era changes.
+     * For example:
+     * <pre>
+     *  6th Jan Showa 64 = ISO 1989-01-06
+     *  7th Jan Showa 64 = ISO 1989-01-07
+     *  8th Jan Heisei 1 = ISO 1989-01-08
+     *  9th Jan Heisei 1 = ISO 1989-01-09
+     * </pre>
      *
      * @param era  the Japanese era, not null
      * @param yearOfEra  the Japanese year-of-era
@@ -192,11 +217,15 @@ public final class JapaneseDate
      *  or if the day-of-month is invalid for the month-year,
      *  or if the date is not a Japanese era
      */
-    public static JapaneseDate of(Era era, int yearOfEra, int month, int dayOfMonth) {
-        if (era instanceof JapaneseEra == false) {
-            throw new ClassCastException("Era must be JapaneseEra");
+    public static JapaneseDate of(JapaneseEra era, int yearOfEra, int month, int dayOfMonth) {
+        Objects.requireNonNull(era, "era");
+        LocalGregorianCalendar.Date jdate = JapaneseChronology.JCAL.newCalendarDate(null);
+        jdate.setEra(era.getPrivateEra()).setDate(yearOfEra, month, dayOfMonth);
+        if (!JapaneseChronology.JCAL.validate(jdate)) {
+            throw new DateTimeException("year, month, and day not valid for Era");
         }
-        return JapaneseDate.of((JapaneseEra) era, yearOfEra, month, dayOfMonth);
+        LocalDate date = LocalDate.of(jdate.getNormalizedYear(), month, dayOfMonth);
+        return new JapaneseDate(era, yearOfEra, date);
     }
 
     /**
@@ -205,6 +234,9 @@ public final class JapaneseDate
      * <p>
      * This returns a {@code JapaneseDate} with the specified fields.
      * The day must be valid for the year and month, otherwise an exception will be thrown.
+     * <p>
+     * The Japanese proleptic year, month and day-of-month are the same as those
+     * in the ISO calendar system. They are not reset when the era changes.
      *
      * @param prolepticYear  the Japanese proleptic-year
      * @param month  the Japanese month-of-year, from 1 to 12
@@ -219,23 +251,31 @@ public final class JapaneseDate
 
     /**
      * Obtains a {@code JapaneseDate} representing a date in the Japanese calendar
-     * system from the proleptic-year and day-of-year fields.
+     * system from the era, year-of-era and day-of-year fields.
      * <p>
      * This returns a {@code JapaneseDate} with the specified fields.
      * The day must be valid for the year, otherwise an exception will be thrown.
+     * <p>
+     * The day-of-year in this factory is expressed relative to the start of the year-of-era.
+     * This definition changes the normal meaning of day-of-year only in those years
+     * where the year-of-era is reset to one due to a change in the era.
+     * For example:
+     * <pre>
+     *  6th Jan Showa 64 = day-of-year 6
+     *  7th Jan Showa 64 = day-of-year 7
+     *  8th Jan Heisei 1 = day-of-year 1
+     *  9th Jan Heisei 1 = day-of-year 2
+     * </pre>
      *
-     * @param prolepticYear  the chronology proleptic-year
+     * @param era  the Japanese era, not null
+     * @param yearOfEra  the Japanese year-of-era
      * @param dayOfYear  the chronology day-of-year, from 1 to 366
      * @return the date in Japanese calendar system, not null
      * @throws DateTimeException if the value of any field is out of range,
      *  or if the day-of-year is invalid for the year
      */
-    public static JapaneseDate ofYearDay(int prolepticYear, int dayOfYear) {
-        LocalDate date = LocalDate.ofYearDay(prolepticYear, dayOfYear);
-        return of(prolepticYear, date.getMonthValue(), date.getDayOfMonth());
-    }
-
     static JapaneseDate ofYearDay(JapaneseEra era, int yearOfEra, int dayOfYear) {
+        Objects.requireNonNull(era, "era");
         CalendarDate firstDay = era.getPrivateEra().getSinceDate();
         LocalGregorianCalendar.Date jdate = JapaneseChronology.JCAL.newCalendarDate(null);
         jdate.setEra(era.getPrivateEra());
@@ -253,32 +293,6 @@ public final class JapaneseDate
         return new JapaneseDate(era, yearOfEra, localdate);
     }
 
-    /**
-     * Obtains a {@code JapaneseDate} representing a date in the Japanese calendar
-     * system from the era, year-of-era, month-of-year and day-of-month fields.
-     * <p>
-     * This returns a {@code JapaneseDate} with the specified fields.
-     * The day must be valid for the year and month, otherwise an exception will be thrown.
-     *
-     * @param era  the Japanese era, not null
-     * @param yearOfEra  the Japanese year-of-era
-     * @param month  the Japanese month-of-year, from 1 to 12
-     * @param dayOfMonth  the Japanese day-of-month, from 1 to 31
-     * @return the date in Japanese calendar system, not null
-     * @throws DateTimeException if the value of any field is out of range,
-     *  or if the day-of-month is invalid for the month-year
-     */
-    static JapaneseDate of(JapaneseEra era, int yearOfEra, int month, int dayOfMonth) {
-        Objects.requireNonNull(era, "era");
-        LocalGregorianCalendar.Date jdate = JapaneseChronology.JCAL.newCalendarDate(null);
-        jdate.setEra(era.getPrivateEra()).setDate(yearOfEra, month, dayOfMonth);
-        if (!JapaneseChronology.JCAL.validate(jdate)) {
-            throw new DateTimeException("year, month, and day not valid for Era");
-        }
-        LocalDate date = LocalDate.of(jdate.getNormalizedYear(), month, dayOfMonth);
-        return new JapaneseDate(era, yearOfEra, date);
-    }
-
     /**
      * Obtains a {@code JapaneseDate} from a temporal object.
      * <p>
@@ -307,6 +321,9 @@ public final class JapaneseDate
      * @param isoDate  the standard local date, validated not null
      */
     JapaneseDate(LocalDate isoDate) {
+        if (isoDate.isBefore(MEIJI_6_ISODATE)) {
+            throw new DateTimeException("JapaneseDate before Meiji 6 is not supported");
+        }
         LocalGregorianCalendar.Date jdate = toPrivateJapaneseDate(isoDate);
         this.era = JapaneseEra.toJapaneseEra(jdate.getEra());
         this.yearOfEra = jdate.getYear();
@@ -322,6 +339,9 @@ public final class JapaneseDate
      * @param isoDate  the standard local date, validated not null
      */
     JapaneseDate(JapaneseEra era, int year, LocalDate isoDate) {
+        if (isoDate.isBefore(MEIJI_6_ISODATE)) {
+            throw new DateTimeException("JapaneseDate before Meiji 6 is not supported");
+        }
         this.era = era;
         this.yearOfEra = year;
         this.isoDate = isoDate;
@@ -366,55 +386,99 @@ public final class JapaneseDate
         return isoDate.lengthOfMonth();
     }
 
+    @Override
+    public int lengthOfYear() {
+        Calendar jcal = Calendar.getInstance(JapaneseChronology.LOCALE);
+        jcal.set(Calendar.ERA, era.getValue() + JapaneseEra.ERA_OFFSET);
+        jcal.set(yearOfEra, isoDate.getMonthValue() - 1, isoDate.getDayOfMonth());
+        return  jcal.getActualMaximum(Calendar.DAY_OF_YEAR);
+    }
+
     //-----------------------------------------------------------------------
+    /**
+     * Checks if the specified field is supported.
+     * <p>
+     * This checks if this date can be queried for the specified field.
+     * If false, then calling the {@link #range(TemporalField) range} and
+     * {@link #get(TemporalField) get} methods will throw an exception.
+     * <p>
+     * If the field is a {@link ChronoField} then the query is implemented here.
+     * The supported fields are:
+     * <ul>
+     * <li>{@code DAY_OF_WEEK}
+     * <li>{@code DAY_OF_MONTH}
+     * <li>{@code DAY_OF_YEAR}
+     * <li>{@code EPOCH_DAY}
+     * <li>{@code MONTH_OF_YEAR}
+     * <li>{@code PROLEPTIC_MONTH}
+     * <li>{@code YEAR_OF_ERA}
+     * <li>{@code YEAR}
+     * <li>{@code ERA}
+     * </ul>
+     * All other {@code ChronoField} instances will return false.
+     * <p>
+     * If the field is not a {@code ChronoField}, then the result of this method
+     * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
+     * passing {@code this} as the argument.
+     * Whether the field is supported is determined by the field.
+     *
+     * @param field  the field to check, null returns false
+     * @return true if the field is supported on this date, false if not
+     */
+    @Override
+    public boolean isSupported(TemporalField field) {
+        if (field == ALIGNED_DAY_OF_WEEK_IN_MONTH || field == ALIGNED_DAY_OF_WEEK_IN_YEAR ||
+                field == ALIGNED_WEEK_OF_MONTH || field == ALIGNED_WEEK_OF_YEAR) {
+            return false;
+        }
+        return ChronoLocalDate.super.isSupported(field);
+    }
+
     @Override
     public ValueRange range(TemporalField field) {
         if (field instanceof ChronoField) {
             if (isSupported(field)) {
                 ChronoField f = (ChronoField) field;
                 switch (f) {
-                    case DAY_OF_MONTH:
-                    case ALIGNED_WEEK_OF_MONTH:
-                        return isoDate.range(field);
-                    case DAY_OF_YEAR:
-                        return actualRange(Calendar.DAY_OF_YEAR);
-                    case YEAR_OF_ERA:
-                        return actualRange(Calendar.YEAR);
+                    case DAY_OF_MONTH: return ValueRange.of(1, lengthOfMonth());
+                    case DAY_OF_YEAR: return ValueRange.of(1, lengthOfYear());
+                    case YEAR_OF_ERA: {
+                        Calendar jcal = Calendar.getInstance(JapaneseChronology.LOCALE);
+                        jcal.set(Calendar.ERA, era.getValue() + JapaneseEra.ERA_OFFSET);
+                        jcal.set(yearOfEra, isoDate.getMonthValue() - 1, isoDate.getDayOfMonth());
+                        return ValueRange.of(1, jcal.getActualMaximum(Calendar.YEAR));
+                    }
                 }
                 return getChronology().range(f);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.rangeRefinedBy(this);
     }
 
-    private ValueRange actualRange(int calendarField) {
-        Calendar jcal = Calendar.getInstance(JapaneseChronology.LOCALE);
-        jcal.set(Calendar.ERA, era.getValue() + JapaneseEra.ERA_OFFSET);  // TODO: cannot calculate this way for SEIREKI
-        jcal.set(yearOfEra, isoDate.getMonthValue() - 1, isoDate.getDayOfMonth());
-        return ValueRange.of(jcal.getActualMinimum(calendarField),
-                jcal.getActualMaximum(calendarField));
-    }
-
     @Override
     public long getLong(TemporalField field) {
         if (field instanceof ChronoField) {
             // same as ISO:
-            // DAY_OF_WEEK, ALIGNED_DAY_OF_WEEK_IN_MONTH, DAY_OF_MONTH, EPOCH_DAY,
-            // ALIGNED_WEEK_OF_MONTH, MONTH_OF_YEAR, PROLEPTIC_MONTH, YEAR
+            // DAY_OF_WEEK, DAY_OF_MONTH, EPOCH_DAY, MONTH_OF_YEAR, PROLEPTIC_MONTH, YEAR
             //
             // calendar specific fields
-            // ALIGNED_DAY_OF_WEEK_IN_YEAR, DAY_OF_YEAR, ALIGNED_WEEK_OF_YEAR, YEAR_OF_ERA, ERA
+            // DAY_OF_YEAR, YEAR_OF_ERA, ERA
             switch ((ChronoField) field) {
+                case ALIGNED_DAY_OF_WEEK_IN_MONTH:
+                case ALIGNED_DAY_OF_WEEK_IN_YEAR:
+                case ALIGNED_WEEK_OF_MONTH:
+                case ALIGNED_WEEK_OF_YEAR:
+                    throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
                 case YEAR_OF_ERA:
                     return yearOfEra;
                 case ERA:
                     return era.getValue();
-                case DAY_OF_YEAR: {
-                    LocalGregorianCalendar.Date jdate = toPrivateJapaneseDate(isoDate);
-                    return JapaneseChronology.JCAL.getDayOfYear(jdate);
-                }
-                // TODO: ALIGNED_DAY_OF_WEEK_IN_YEAR and ALIGNED_WEEK_OF_YEAR ???
+                case DAY_OF_YEAR:
+                    Calendar jcal = Calendar.getInstance(JapaneseChronology.LOCALE);
+                    jcal.set(Calendar.ERA, era.getValue() + JapaneseEra.ERA_OFFSET);
+                    jcal.set(yearOfEra, isoDate.getMonthValue() - 1, isoDate.getDayOfMonth());
+                    return jcal.get(Calendar.DAY_OF_YEAR);
             }
             return isoDate.getLong(field);
         }
@@ -444,7 +508,7 @@ public final class JapaneseDate
     public JapaneseDate with(TemporalField field, long newValue) {
         if (field instanceof ChronoField) {
             ChronoField f = (ChronoField) field;
-            if (getLong(f) == newValue) {
+            if (getLong(f) == newValue) {  // getLong() validates for supported fields
                 return this;
             }
             switch (f) {
@@ -464,10 +528,9 @@ public final class JapaneseDate
                 }
             }
             // YEAR, PROLEPTIC_MONTH and others are same as ISO
-            // TODO: review other fields, such as WEEK_OF_YEAR
             return with(isoDate.with(field, newValue));
         }
-        return ChronoLocalDate.super.with(field, newValue);
+        return super.with(field, newValue);
     }
 
     /**
@@ -592,13 +655,14 @@ public final class JapaneseDate
     }
 
     @Override        // for javadoc and covariant return type
+    @SuppressWarnings("unchecked")
     public final ChronoLocalDateTime<JapaneseDate> atTime(LocalTime localTime) {
-        return super.atTime(localTime);
+        return (ChronoLocalDateTime<JapaneseDate>)super.atTime(localTime);
     }
 
     @Override
-    public Period periodUntil(ChronoLocalDate<?> endDate) {
-        return isoDate.periodUntil(endDate);
+    public Period until(ChronoLocalDate endDate) {
+        return isoDate.until(endDate);
     }
 
     @Override  // override for performance
@@ -624,14 +688,6 @@ public final class JapaneseDate
         return getChronology().getId().hashCode() ^ isoDate.hashCode();
     }
 
-    @Override
-    public String toString() {
-        if (era == JapaneseEra.SEIREKI) {
-            return getChronology().getId() + " " + isoDate.toString();
-        }
-        return super.toString();
-    }
-
     //-----------------------------------------------------------------------
     private Object writeReplace() {
         return new Ser(Ser.JAPANESE_DATE_TYPE, this);

src/share/classes/java/time/chrono/JapaneseEra.java

@@ -61,6 +61,7 @@
  */
 package java.time.chrono;
 
+import static java.time.chrono.JapaneseDate.MEIJI_6_ISODATE;
 import static java.time.temporal.ChronoField.ERA;
 
 import java.io.DataInput;
@@ -84,12 +85,9 @@ import sun.util.calendar.CalendarDate;
  * An era in the Japanese Imperial calendar system.
  * <p>
  * This class defines the valid eras for the Japanese chronology.
- * Only Meiji (1868-09-08 - 1912-07-29) and later eras are supported.
- * Japan introduced the Gregorian calendar since Meiji 6. The dates
- * between Meiji 1 - 5 are not historically correct.
- * The older eras are recognized as Seireki (Western calendar) era,
- * and the year of era of Seireki is proleptic Gregorian year.
- * (The Julian to Gregorian transition is not supported.)
+ * Japan introduced the Gregorian calendar starting with Meiji 6.
+ * Only Meiji and later eras are supported;
+ * dates before Meiji 6, January 1 are not supported.
  *
  * @implSpec
  * This class is immutable and thread-safe.
@@ -100,16 +98,11 @@ public final class JapaneseEra
         implements Era, Serializable {
 
     // The offset value to 0-based index from the era value.
-    // i.e., getValue() + ERA_OFFSET == 0-based index; except that -999 is mapped to zero
+    // i.e., getValue() + ERA_OFFSET == 0-based index
     static final int ERA_OFFSET = 2;
 
     static final sun.util.calendar.Era[] ERA_CONFIG;
 
-    /**
-     * The singleton instance for the before Meiji era ( - 1868-09-07)
-     * which has the value -999.
-     */
-    public static final JapaneseEra SEIREKI = new JapaneseEra(-999, LocalDate.MIN);
     /**
      * The singleton instance for the 'Meiji' era (1868-09-08 - 1912-07-29)
      * which has the value -1.
@@ -144,17 +137,13 @@ public final class JapaneseEra
     private static final JapaneseEra[] KNOWN_ERAS;
 
     static {
-        sun.util.calendar.Era[] sunEras = JapaneseChronology.JCAL.getEras();
-        ERA_CONFIG = new sun.util.calendar.Era[sunEras.length + 1];
-        for (int i = 1; i < ERA_CONFIG.length; i++) {
-            ERA_CONFIG[i] = sunEras[i - 1];
-        }
+        ERA_CONFIG = JapaneseChronology.JCAL.getEras();
+
         KNOWN_ERAS = new JapaneseEra[ERA_CONFIG.length];
-        KNOWN_ERAS[0] = SEIREKI;
-        KNOWN_ERAS[1] = MEIJI;
-        KNOWN_ERAS[2] = TAISHO;
-        KNOWN_ERAS[3] = SHOWA;
-        KNOWN_ERAS[4] = HEISEI;
+        KNOWN_ERAS[0] = MEIJI;
+        KNOWN_ERAS[1] = TAISHO;
+        KNOWN_ERAS[2] = SHOWA;
+        KNOWN_ERAS[3] = HEISEI;
         for (int i = N_ERA_CONSTANTS; i < ERA_CONFIG.length; i++) {
             CalendarDate date = ERA_CONFIG[i].getSinceDate();
             LocalDate isoDate = LocalDate.of(date.getYear(), date.getMonth(), date.getDayOfMonth());
@@ -203,10 +192,8 @@ public final class JapaneseEra
     //-----------------------------------------------------------------------
     /**
      * Returns the Sun private Era instance corresponding to this {@code JapaneseEra}.
-     * SEIREKI doesn't have its corresponding one.
      *
-     * @return the Sun private Era instance for this {@code JapaneseEra},
-     *         or null for SEIREKI.
+     * @return the Sun private Era instance for this {@code JapaneseEra}.
      */
     sun.util.calendar.Era getPrivateEra() {
         return ERA_CONFIG[ordinal(eraValue)];
@@ -218,16 +205,14 @@ public final class JapaneseEra
      * <p>
      * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1
      * Later era is numbered 2 ({@link #HEISEI}). Earlier eras are numbered 0 ({@link #TAISHO}),
-     * -1 ({@link #MEIJI}), only Meiji and later eras are supported. The prior to Meiji,
-     * {@link #SEIREKI} is used.
+     * -1 ({@link #MEIJI}), only Meiji and later eras are supported.
      *
      * @param japaneseEra  the era to represent
      * @return the {@code JapaneseEra} singleton, not null
      * @throws DateTimeException if the value is invalid
      */
     public static JapaneseEra of(int japaneseEra) {
-        if (japaneseEra != SEIREKI.eraValue &&
-            (japaneseEra < MEIJI.eraValue || japaneseEra > HEISEI.eraValue)) {
+        if (japaneseEra < MEIJI.eraValue || japaneseEra > HEISEI.eraValue) {
             throw new DateTimeException("Invalid era: " + japaneseEra);
         }
         return KNOWN_ERAS[ordinal(japaneseEra)];
@@ -276,22 +261,25 @@ public final class JapaneseEra
      * @return the Era singleton, never null
      */
     static JapaneseEra from(LocalDate date) {
+        if (date.isBefore(MEIJI_6_ISODATE)) {
+            throw new DateTimeException("JapaneseDate before Meiji 6 are not supported");
+        }
         for (int i = KNOWN_ERAS.length - 1; i > 0; i--) {
             JapaneseEra era = KNOWN_ERAS[i];
             if (date.compareTo(era.since) >= 0) {
                 return era;
             }
         }
-        return SEIREKI;
+        return null;
     }
 
     static JapaneseEra toJapaneseEra(sun.util.calendar.Era privateEra) {
-        for (int i = ERA_CONFIG.length - 1; i > 0; i--) {
+        for (int i = ERA_CONFIG.length - 1; i >= 0; i--) {
             if (ERA_CONFIG[i].equals(privateEra)) {
                 return KNOWN_ERAS[i];
             }
         }
-        return SEIREKI;
+        return null;
     }
 
     static sun.util.calendar.Era privateEraFrom(LocalDate isoDate) {
@@ -306,13 +294,13 @@ public final class JapaneseEra
 
     /**
      * Returns the index into the arrays from the Era value.
-     * the eraValue is a valid Era number, -999, -1..2.
+     * the eraValue is a valid Era number, -1..2.
      *
      * @param eraValue  the era value to convert to the index
      * @return the index of the current Era
      */
     private static int ordinal(int eraValue) {
-        return (eraValue == SEIREKI.eraValue) ? 0 : eraValue + ERA_OFFSET;
+        return eraValue + ERA_OFFSET - 1;
     }
 
     //-----------------------------------------------------------------------
@@ -321,7 +309,7 @@ public final class JapaneseEra
      * <p>
      * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1.
      * Later eras are numbered from 2 ({@link #HEISEI}).
-     * Earlier eras are numbered 0 ({@link #TAISHO}), -1 ({@link #MEIJI}), and -999 ({@link #SEIREKI}).
+     * Earlier eras are numbered 0 ({@link #TAISHO}), -1 ({@link #MEIJI})).
      *
      * @return the era value
      */
@@ -374,11 +362,7 @@ public final class JapaneseEra
     }
 
     String getName() {
-        int index = ordinal(getValue());
-        if (index == 0) {
-            return "Seireki";
-        }
-        return ERA_CONFIG[index].getName();
+        return ERA_CONFIG[ordinal(getValue())].getName();
     }
 
     @Override

src/share/classes/java/time/chrono/MinguoChronology.java

@@ -65,12 +65,15 @@ import java.time.DateTimeException;
 import java.time.Instant;
 import java.time.LocalDate;
 import java.time.ZoneId;
+import java.time.format.ResolverStyle;
 import java.time.temporal.ChronoField;
 import java.time.temporal.TemporalAccessor;
+import java.time.temporal.TemporalField;
 import java.time.temporal.ValueRange;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Locale;
+import java.util.Map;
 
 /**
  * The Minguo calendar system.
@@ -253,16 +256,19 @@ public final class MinguoChronology extends Chronology implements Serializable {
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public ChronoLocalDateTime<MinguoDate> localDateTime(TemporalAccessor temporal) {
         return (ChronoLocalDateTime<MinguoDate>)super.localDateTime(temporal);
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public ChronoZonedDateTime<MinguoDate> zonedDateTime(TemporalAccessor temporal) {
         return (ChronoZonedDateTime<MinguoDate>)super.zonedDateTime(temporal);
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public ChronoZonedDateTime<MinguoDate> zonedDateTime(Instant instant, ZoneId zone) {
         return (ChronoZonedDateTime<MinguoDate>)super.zonedDateTime(instant, zone);
     }
@@ -292,7 +298,7 @@ public final class MinguoChronology extends Chronology implements Serializable {
     }
 
     @Override
-    public Era eraOf(int eraValue) {
+    public MinguoEra eraOf(int eraValue) {
         return MinguoEra.of(eraValue);
     }
 
@@ -321,4 +327,10 @@ public final class MinguoChronology extends Chronology implements Serializable {
         return field.range();
     }
 
+    //-----------------------------------------------------------------------
+    @Override  // override for return type
+    public MinguoDate resolveDate(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
+        return (MinguoDate) super.resolveDate(fieldValues, resolverStyle);
+    }
+
 }

src/share/classes/java/time/chrono/MinguoDate.java

@@ -96,7 +96,7 @@ import java.util.Objects;
  */
 public final class MinguoDate
         extends ChronoDateImpl<MinguoDate>
-        implements ChronoLocalDate<MinguoDate>, Serializable {
+        implements ChronoLocalDate, Serializable {
 
     /**
      * Serialization version.
@@ -152,7 +152,7 @@ public final class MinguoDate
      * @throws DateTimeException if the current date cannot be obtained
      */
     public static MinguoDate now(Clock clock) {
-        return MinguoChronology.INSTANCE.date(LocalDate.now(clock));
+        return new MinguoDate(LocalDate.now(clock));
     }
 
     /**
@@ -264,7 +264,7 @@ public final class MinguoDate
                 }
                 return getChronology().range(f);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.rangeRefinedBy(this);
     }
@@ -325,7 +325,7 @@ public final class MinguoDate
             }
             return with(isoDate.with(field, newValue));
         }
-        return ChronoLocalDate.super.with(field, newValue);
+        return super.with(field, newValue);
     }
 
     /**
@@ -369,6 +369,11 @@ public final class MinguoDate
         return with(isoDate.plusMonths(months));
     }
 
+    @Override
+    MinguoDate plusWeeks(long weeksToAdd) {
+        return super.plusWeeks(weeksToAdd);
+    }
+
     @Override
     MinguoDate plusDays(long days) {
         return with(isoDate.plusDays(days));
@@ -384,11 +389,6 @@ public final class MinguoDate
         return super.minus(amountToAdd, unit);
     }
 
-    @Override
-    MinguoDate plusWeeks(long weeksToAdd) {
-        return super.plusWeeks(weeksToAdd);
-    }
-
     @Override
     MinguoDate minusYears(long yearsToSubtract) {
         return super.minusYears(yearsToSubtract);
@@ -414,13 +414,14 @@ public final class MinguoDate
     }
 
     @Override        // for javadoc and covariant return type
+    @SuppressWarnings("unchecked")
     public final ChronoLocalDateTime<MinguoDate> atTime(LocalTime localTime) {
-        return super.atTime(localTime);
+        return (ChronoLocalDateTime<MinguoDate>)super.atTime(localTime);
     }
 
     @Override
-    public Period periodUntil(ChronoLocalDate<?> endDate) {
-        return isoDate.periodUntil(endDate);
+    public Period until(ChronoLocalDate endDate) {
+        return isoDate.until(endDate);
     }
 
     @Override  // override for performance
@@ -458,7 +459,7 @@ public final class MinguoDate
         out.writeByte(get(DAY_OF_MONTH));
     }
 
-    static ChronoLocalDate<?> readExternal(DataInput in) throws IOException {
+    static MinguoDate readExternal(DataInput in) throws IOException {
         int year = in.readInt();
         int month = in.readByte();
         int dayOfMonth = in.readByte();

src/share/classes/java/time/chrono/ThaiBuddhistChronology.java

@@ -65,13 +65,16 @@ import java.time.DateTimeException;
 import java.time.Instant;
 import java.time.LocalDate;
 import java.time.ZoneId;
+import java.time.format.ResolverStyle;
 import java.time.temporal.ChronoField;
 import java.time.temporal.TemporalAccessor;
+import java.time.temporal.TemporalField;
 import java.time.temporal.ValueRange;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
+import java.util.Map;
 
 /**
  * The Thai Buddhist calendar system.
@@ -289,16 +292,19 @@ public final class ThaiBuddhistChronology extends Chronology implements Serializ
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public ChronoLocalDateTime<ThaiBuddhistDate> localDateTime(TemporalAccessor temporal) {
         return (ChronoLocalDateTime<ThaiBuddhistDate>)super.localDateTime(temporal);
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public ChronoZonedDateTime<ThaiBuddhistDate> zonedDateTime(TemporalAccessor temporal) {
         return (ChronoZonedDateTime<ThaiBuddhistDate>)super.zonedDateTime(temporal);
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public ChronoZonedDateTime<ThaiBuddhistDate> zonedDateTime(Instant instant, ZoneId zone) {
         return (ChronoZonedDateTime<ThaiBuddhistDate>)super.zonedDateTime(instant, zone);
     }
@@ -328,7 +334,7 @@ public final class ThaiBuddhistChronology extends Chronology implements Serializ
     }
 
     @Override
-    public Era eraOf(int eraValue) {
+    public ThaiBuddhistEra eraOf(int eraValue) {
         return ThaiBuddhistEra.of(eraValue);
     }
 
@@ -357,4 +363,10 @@ public final class ThaiBuddhistChronology extends Chronology implements Serializ
         return field.range();
     }
 
+    //-----------------------------------------------------------------------
+    @Override  // override for return type
+    public ThaiBuddhistDate resolveDate(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
+        return (ThaiBuddhistDate) super.resolveDate(fieldValues, resolverStyle);
+    }
+
 }

src/share/classes/java/time/chrono/ThaiBuddhistDate.java

@@ -96,7 +96,7 @@ import java.util.Objects;
  */
 public final class ThaiBuddhistDate
         extends ChronoDateImpl<ThaiBuddhistDate>
-        implements ChronoLocalDate<ThaiBuddhistDate>, Serializable {
+        implements ChronoLocalDate, Serializable {
 
     /**
      * Serialization version.
@@ -152,7 +152,7 @@ public final class ThaiBuddhistDate
      * @throws DateTimeException if the current date cannot be obtained
      */
     public static ThaiBuddhistDate now(Clock clock) {
-        return ThaiBuddhistChronology.INSTANCE.date(LocalDate.now(clock));
+        return new ThaiBuddhistDate(LocalDate.now(clock));
     }
 
     /**
@@ -264,7 +264,7 @@ public final class ThaiBuddhistDate
                 }
                 return getChronology().range(f);
             }
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.rangeRefinedBy(this);
     }
@@ -325,7 +325,7 @@ public final class ThaiBuddhistDate
             }
             return with(isoDate.with(field, newValue));
         }
-        return ChronoLocalDate.super.with(field, newValue);
+        return super.with(field, newValue);
     }
 
     /**
@@ -414,13 +414,14 @@ public final class ThaiBuddhistDate
     }
 
     @Override        // for javadoc and covariant return type
+    @SuppressWarnings("unchecked")
     public final ChronoLocalDateTime<ThaiBuddhistDate> atTime(LocalTime localTime) {
-        return super.atTime(localTime);
+        return (ChronoLocalDateTime<ThaiBuddhistDate>) super.atTime(localTime);
     }
 
     @Override
-    public Period periodUntil(ChronoLocalDate<?> endDate) {
-        return isoDate.periodUntil(endDate);
+    public Period until(ChronoLocalDate endDate) {
+        return isoDate.until(endDate);
     }
 
     @Override  // override for performance

src/share/classes/java/time/chrono/package-info.java

@@ -103,7 +103,7 @@
  *   // Enumerate the list of available calendars and print todays date for each.
  *       Set<Chronology> chronos = Chronology.getAvailableChronologies();
  *       for (Chronology chrono : chronos) {
- *           ChronoLocalDate<?> date = chrono.dateNow();
+ *           ChronoLocalDate date = chrono.dateNow();
  *           System.out.printf("   %20s: %s%n", chrono.getId(), date.toString());
  *       }
  * </pre>
@@ -113,7 +113,7 @@
  * </p>
  * <pre>
  *   // Print the Thai Buddhist date
- *       ChronoLocalDate&lt;?&gt; now1 = Chronology.of("ThaiBuddhist").dateNow();
+ *       ChronoLocalDate now1 = Chronology.of("ThaiBuddhist").dateNow();
  *       int day = now1.get(ChronoField.DAY_OF_MONTH);
  *       int dow = now1.get(ChronoField.DAY_OF_WEEK);
  *       int month = now1.get(ChronoField.MONTH_OF_YEAR);
@@ -121,10 +121,10 @@
  *       System.out.printf("  Today is %s %s %d-%s-%d%n", now1.getChronology().getId(),
  *                 dow, day, month, year);
  *   // Print today's date and the last day of the year for the Thai Buddhist Calendar.
- *       ChronoLocalDate&lt;?&gt; first = now1
+ *       ChronoLocalDate first = now1
  *                 .with(ChronoField.DAY_OF_MONTH, 1)
  *                 .with(ChronoField.MONTH_OF_YEAR, 1);
- *       ChronoLocalDate&lt;?&gt; last = first
+ *       ChronoLocalDate last = first
  *                 .plus(1, ChronoUnit.YEARS)
  *                 .minus(1, ChronoUnit.DAYS);
  *       System.out.printf("  %s: 1st of year: %s; end of year: %s%n", last.getChronology().getId(),

src/share/classes/java/time/format/DateTimeFormatter.java

@@ -265,7 +265,7 @@ import java.util.Set;
  * <p>
  * For example:
  * <blockquote><pre>
- *  DateTimeFormatter formatter = DateTimeFormatter.pattern("yyyy MM dd");
+ *  DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy MM dd");
  *  String text = date.toString(formatter);
  *  LocalDate date = LocalDate.parse(text, formatter);
  * </pre></blockquote>
@@ -460,7 +460,7 @@ import java.util.Set;
  * <li>The {@code ChronoField} time fields are resolved.
  * This is documented on {@link ChronoField} and is the same for all chronologies.
  * <li>Any fields that are not {@code ChronoField} are processed.
- * This is achieved using {@link TemporalField#resolve(TemporalAccessor, long, ResolverStyle)}.
+ * This is achieved using {@link TemporalField#resolve(Map, Chronology, ZoneId, ResolverStyle)}.
  * Documentation about field resolution is located in the implementation
  * of {@code TemporalField}.
  * <li>The {@code ChronoField} date and time fields are re-resolved.

src/share/classes/java/time/format/DateTimeFormatterBuilder.java

@@ -77,7 +77,6 @@ import java.math.BigInteger;
 import java.math.RoundingMode;
 import java.text.ParsePosition;
 import java.time.DateTimeException;
-import java.time.Duration;
 import java.time.Instant;
 import java.time.LocalDateTime;
 import java.time.ZoneId;
@@ -962,12 +961,9 @@ public final class DateTimeFormatterBuilder {
      * <pre>
      *   "Europe/London"           -- ZoneId.of("Europe/London")
      *   "Z"                       -- ZoneOffset.UTC
-     *   "UT"                      -- ZoneOffset.UTC
-     *   "UTC"                     -- ZoneOffset.UTC
-     *   "GMT"                     -- ZoneOffset.UTC
-     *   "UT0"                     -- ZoneOffset.UTC
-     *   "UTC0"                    -- ZoneOffset.UTC
-     *   "GMT0"                    -- ZoneOffset.UTC
+     *   "UT"                      -- ZoneId.of("UT")
+     *   "UTC"                     -- ZoneId.of("UTC")
+     *   "GMT"                     -- ZoneId.of("GMT")
      *   "+01:30"                  -- ZoneOffset.of("+01:30")
      *   "UT+01:30"                -- ZoneOffset.of("+01:30")
      *   "UTC+01:30"               -- ZoneOffset.of("+01:30")
@@ -1016,12 +1012,9 @@ public final class DateTimeFormatterBuilder {
      * <pre>
      *   "Europe/London"           -- ZoneId.of("Europe/London")
      *   "Z"                       -- ZoneOffset.UTC
-     *   "UT"                      -- ZoneOffset.UTC
-     *   "UTC"                     -- ZoneOffset.UTC
-     *   "GMT"                     -- ZoneOffset.UTC
-     *   "UT0"                     -- ZoneOffset.UTC
-     *   "UTC0"                    -- ZoneOffset.UTC
-     *   "GMT0"                    -- ZoneOffset.UTC
+     *   "UT"                      -- ZoneId.of("UT")
+     *   "UTC"                     -- ZoneId.of("UTC")
+     *   "GMT"                     -- ZoneId.of("GMT")
      *   "+01:30"                  -- ZoneOffset.of("+01:30")
      *   "UT+01:30"                -- ZoneOffset.of("+01:30")
      *   "UTC+01:30"               -- ZoneOffset.of("+01:30")
@@ -1077,16 +1070,13 @@ public final class DateTimeFormatterBuilder {
      * <pre>
      *   "Europe/London"           -- ZoneId.of("Europe/London")
      *   "Z"                       -- ZoneOffset.UTC
-     *   "UT"                      -- ZoneOffset.UTC
-     *   "UTC"                     -- ZoneOffset.UTC
-     *   "GMT"                     -- ZoneOffset.UTC
-     *   "UT0"                     -- ZoneOffset.UTC
-     *   "UTC0"                    -- ZoneOffset.UTC
-     *   "GMT0"                    -- ZoneOffset.UTC
+     *   "UT"                      -- ZoneId.of("UT")
+     *   "UTC"                     -- ZoneId.of("UTC")
+     *   "GMT"                     -- ZoneId.of("GMT")
      *   "+01:30"                  -- ZoneOffset.of("+01:30")
-     *   "UT+01:30"                -- ZoneOffset.of("+01:30")
-     *   "UTC+01:30"               -- ZoneOffset.of("+01:30")
-     *   "GMT+01:30"               -- ZoneOffset.of("+01:30")
+     *   "UT+01:30"                -- ZoneOffset.of("UT+01:30")
+     *   "UTC+01:30"               -- ZoneOffset.of("UTC+01:30")
+     *   "GMT+01:30"               -- ZoneOffset.of("GMT+01:30")
      * </pre>
      * <p>
      * Note that this method is is identical to {@code appendZoneId()} except
@@ -2530,7 +2520,7 @@ public final class DateTimeFormatterBuilder {
             DecimalStyle decimalStyle = context.getDecimalStyle();
             String str = (value == Long.MIN_VALUE ? "9223372036854775808" : Long.toString(Math.abs(value)));
             if (str.length() > maxWidth) {
-                throw new DateTimeException("Field " + field.getName() +
+                throw new DateTimeException("Field " + field +
                     " cannot be printed as the value " + value +
                     " exceeds the maximum print width of " + maxWidth);
             }
@@ -2555,7 +2545,7 @@ public final class DateTimeFormatterBuilder {
                         buf.append(decimalStyle.getNegativeSign());
                         break;
                     case NOT_NEGATIVE:
-                        throw new DateTimeException("Field " + field.getName() +
+                        throw new DateTimeException("Field " + field +
                             " cannot be printed as the value " + value +
                             " cannot be negative according to the SignStyle");
                 }
@@ -2699,12 +2689,12 @@ public final class DateTimeFormatterBuilder {
         @Override
         public String toString() {
             if (minWidth == 1 && maxWidth == 19 && signStyle == SignStyle.NORMAL) {
-                return "Value(" + field.getName() + ")";
+                return "Value(" + field + ")";
             }
             if (minWidth == maxWidth && signStyle == SignStyle.NOT_NEGATIVE) {
-                return "Value(" + field.getName() + "," + minWidth + ")";
+                return "Value(" + field + "," + minWidth + ")";
             }
-            return "Value(" + field.getName() + "," + minWidth + "," + maxWidth + "," + signStyle + ")";
+            return "Value(" + field + "," + minWidth + "," + maxWidth + "," + signStyle + ")";
         }
     }
 
@@ -2817,7 +2807,7 @@ public final class DateTimeFormatterBuilder {
 
         @Override
         public String toString() {
-            return "ReducedValue(" + field.getName() + "," + minWidth + "," + maxWidth + "," + baseValue + ")";
+            return "ReducedValue(" + field + "," + minWidth + "," + maxWidth + "," + baseValue + ")";
         }
     }
 
@@ -2842,7 +2832,7 @@ public final class DateTimeFormatterBuilder {
         FractionPrinterParser(TemporalField field, int minWidth, int maxWidth, boolean decimalPoint) {
             Objects.requireNonNull(field, "field");
             if (field.range().isFixed() == false) {
-                throw new IllegalArgumentException("Field must have a fixed set of values: " + field.getName());
+                throw new IllegalArgumentException("Field must have a fixed set of values: " + field);
             }
             if (minWidth < 0 || minWidth > 9) {
                 throw new IllegalArgumentException("Minimum width must be from 0 to 9 inclusive but was " + minWidth);
@@ -2984,7 +2974,7 @@ public final class DateTimeFormatterBuilder {
         @Override
         public String toString() {
             String decimal = (decimalPoint ? ",DecimalPoint" : "");
-            return "Fraction(" + field.getName() + "," + minWidth + "," + maxWidth + decimal + ")";
+            return "Fraction(" + field + "," + minWidth + "," + maxWidth + decimal + ")";
         }
     }
 
@@ -3079,9 +3069,9 @@ public final class DateTimeFormatterBuilder {
         @Override
         public String toString() {
             if (textStyle == TextStyle.FULL) {
-                return "Text(" + field.getName() + ")";
+                return "Text(" + field + ")";
             }
-            return "Text(" + field.getName() + "," + textStyle + ")";
+            return "Text(" + field + "," + textStyle + ")";
         }
     }
 
@@ -3756,17 +3746,17 @@ public final class DateTimeFormatterBuilder {
             // handle fixed time-zone IDs
             char nextChar = text.charAt(position);
             if (nextChar == '+' || nextChar == '-') {
-                return parseOffsetBased(context, text, position, OffsetIdPrinterParser.INSTANCE_ID_Z);
+                return parseOffsetBased(context, text, position, position, OffsetIdPrinterParser.INSTANCE_ID_Z);
             } else if (length >= position + 2) {
                 char nextNextChar = text.charAt(position + 1);
                 if (context.charEquals(nextChar, 'U') && context.charEquals(nextNextChar, 'T')) {
                     if (length >= position + 3 && context.charEquals(text.charAt(position + 2), 'C')) {
-                        return parseOffsetBased(context, text, position + 3, OffsetIdPrinterParser.INSTANCE_ID_ZERO);
+                        return parseOffsetBased(context, text, position, position + 3, OffsetIdPrinterParser.INSTANCE_ID_ZERO);
                     }
-                    return parseOffsetBased(context, text, position + 2, OffsetIdPrinterParser.INSTANCE_ID_ZERO);
+                    return parseOffsetBased(context, text, position, position + 2, OffsetIdPrinterParser.INSTANCE_ID_ZERO);
                 } else if (context.charEquals(nextChar, 'G') && length >= position + 3 &&
                         context.charEquals(nextNextChar, 'M') && context.charEquals(text.charAt(position + 2), 'T')) {
-                    return parseOffsetBased(context, text, position + 3, OffsetIdPrinterParser.INSTANCE_ID_ZERO);
+                    return parseOffsetBased(context, text, position, position + 3, OffsetIdPrinterParser.INSTANCE_ID_ZERO);
                 }
             }
 
@@ -3785,20 +3775,49 @@ public final class DateTimeFormatterBuilder {
             return ppos.getIndex();
         }
 
-        private int parseOffsetBased(DateTimeParseContext context, CharSequence text, int position, OffsetIdPrinterParser parser) {
+        /**
+         * Parse an offset following a prefix and set the ZoneId if it is valid.
+         * To matching the parsing of ZoneId.of the values are not normalized
+         * to ZoneOffsets.
+         *
+         * @param context the parse context
+         * @param text the input text
+         * @param prefixPos start of the prefix
+         * @param position start of text after the prefix
+         * @param parser parser for the value after the prefix
+         * @return the position after the parse
+         */
+        private int parseOffsetBased(DateTimeParseContext context, CharSequence text, int prefixPos, int position, OffsetIdPrinterParser parser) {
+            String prefix = text.toString().substring(prefixPos, position).toUpperCase();
+            if (position >= text.length()) {
+                context.setParsed(ZoneId.of(prefix));
+                return position;
+            }
+
+            // '0' or 'Z' after prefix is not part of a valid ZoneId; use bare prefix
+            if (text.charAt(position) == '0' ||
+                context.charEquals(text.charAt(position), 'Z')) {
+                context.setParsed(ZoneId.of(prefix));
+                return position;
+            }
+
             DateTimeParseContext newContext = context.copy();
             int endPos = parser.parse(newContext, text, position);
-            if (endPos < 0) {
-                if (parser == OffsetIdPrinterParser.INSTANCE_ID_Z) {
-                    return ~position;
+            try {
+                if (endPos < 0) {
+                    if (parser == OffsetIdPrinterParser.INSTANCE_ID_Z) {
+                        return ~prefixPos;
+                    }
+                    context.setParsed(ZoneId.of(prefix));
+                    return position;
                 }
-                context.setParsed(ZoneOffset.UTC);
-                return position;
+                int offset = (int) newContext.getParsed(OFFSET_SECONDS).longValue();
+                ZoneOffset zoneOffset = ZoneOffset.ofTotalSeconds(offset);
+                context.setParsed(ZoneId.ofOffset(prefix, zoneOffset));
+                return endPos;
+            } catch (DateTimeException dte) {
+                return ~prefixPos;
             }
-            int offset = (int) newContext.getParsed(OFFSET_SECONDS).longValue();
-            ZoneId zone = ZoneOffset.ofTotalSeconds(offset);
-            context.setParsed(zone);
-            return endPos;
         }
 
         @Override

src/share/classes/java/time/format/DateTimePrintContext.java

@@ -157,7 +157,7 @@ final class DateTimePrintContext {
             }
         }
         final ZoneId effectiveZone = (overrideZone != null ? overrideZone : temporalZone);
-        final ChronoLocalDate<?> effectiveDate;
+        final ChronoLocalDate effectiveDate;
         if (overrideChrono != null) {
             if (temporal.isSupported(EPOCH_DAY)) {
                 effectiveDate = effectiveChrono.date(temporal);

src/share/classes/java/time/format/Parsed.java

@@ -143,7 +143,7 @@ final class Parsed implements TemporalAccessor {
     /**
      * The resolved date.
      */
-    private ChronoLocalDate<?> date;
+    private ChronoLocalDate date;
     /**
      * The resolved time.
      */
@@ -197,7 +197,7 @@ final class Parsed implements TemporalAccessor {
             return time.getLong(field);
         }
         if (field instanceof ChronoField) {
-            throw new UnsupportedTemporalTypeException("Unsupported field: " + field.getName());
+            throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
         }
         return field.getFrom(this);
     }
@@ -255,42 +255,34 @@ final class Parsed implements TemporalAccessor {
         // if any other fields, handle them
         // any lenient date resolution should return epoch-day
         if (fieldValues.size() > 0) {
-            boolean changed = false;
+            int changedCount = 0;
             outer:
-            while (true) {
+            while (changedCount < 50) {
                 for (Map.Entry<TemporalField, Long> entry : fieldValues.entrySet()) {
                     TemporalField targetField = entry.getKey();
-                    Map<TemporalField, Long> changes = targetField.resolve(this, entry.getValue(), resolverStyle);
-                    if (changes != null) {
-                        changed = true;
-                        resolveFieldsMakeChanges(targetField, changes);
-                        fieldValues.remove(targetField);  // helps avoid infinite loops
+                    ChronoLocalDate resolvedDate = targetField.resolve(fieldValues, chrono, zone, resolverStyle);
+                    if (resolvedDate != null) {
+                        updateCheckConflict(resolvedDate);
+                        changedCount++;
+                        continue outer;  // have to restart to avoid concurrent modification
+                    } else if (fieldValues.containsKey(targetField) == false) {
+                        changedCount++;
                         continue outer;  // have to restart to avoid concurrent modification
                     }
                 }
                 break;
             }
+            if (changedCount == 50) {  // catch infinite loops
+                throw new DateTimeException("One of the parsed fields has an incorrectly implemented resolve method");
+            }
             // if something changed then have to redo ChronoField resolve
-            if (changed) {
+            if (changedCount > 0) {
                 resolveDateFields();
                 resolveTimeFields();
             }
         }
     }
 
-    private void resolveFieldsMakeChanges(TemporalField targetField, Map<TemporalField, Long> changes) {
-        for (Map.Entry<TemporalField, Long> change : changes.entrySet()) {
-            TemporalField changeField = change.getKey();
-            Long changeValue = change.getValue();
-            Objects.requireNonNull(changeField, "changeField");
-            if (changeValue != null) {
-                updateCheckConflict(targetField, changeField, changeValue);
-            } else {
-                fieldValues.remove(changeField);
-            }
-        }
-    }
-
     private void updateCheckConflict(TemporalField targetField, TemporalField changeField, Long changeValue) {
         Long old = fieldValues.put(changeField, changeValue);
         if (old != null && old.longValue() != changeValue.longValue()) {
@@ -305,7 +297,7 @@ final class Parsed implements TemporalAccessor {
         updateCheckConflict(chrono.resolveDate(fieldValues, resolverStyle));
     }
 
-    private void updateCheckConflict(ChronoLocalDate<?> cld) {
+    private void updateCheckConflict(ChronoLocalDate cld) {
         if (date != null) {
             if (cld != null && date.equals(cld) == false) {
                 throw new DateTimeException("Conflict found: Fields resolved to two different dates: " + date + " " + cld);

src/share/classes/java/time/temporal/ChronoField.java

@@ -403,6 +403,12 @@ public enum ChronoField implements TemporalField {
      * Non-ISO calendar systems should implement this field using the most recognized
      * day-of-year values for users of the calendar system.
      * Normally, this is a count of days from 1 to the length of the year.
+     * <p>
+     * Note that a non-ISO calendar system may have year numbering system that changes
+     * at a different point to the natural reset in the month numbering. An example
+     * of this is the Japanese calendar system where a change of era, which resets
+     * the year number to 1, can happen on any date. The era and year reset also cause
+     * the day-of-year to be reset to 1, but not the month-of-year or day-of-month.
      */
     DAY_OF_YEAR("DayOfYear", DAYS, YEARS, ValueRange.of(1, 365, 366)),
     /**
@@ -559,12 +565,11 @@ public enum ChronoField implements TemporalField {
      * <p>
      * This represents the concept of the sequential count of seconds where
      * 1970-01-01T00:00Z (ISO) is zero.
-     * This field may be used with {@link #NANO_OF_DAY} to represent the fraction of the day.
+     * This field may be used with {@link #NANO_OF_SECOND} to represent the fraction of the second.
      * <p>
      * An {@link Instant} represents an instantaneous point on the time-line.
-     * On their own they have no elements which allow a local date-time to be obtained.
-     * Only when paired with an offset or time-zone can the local date or time be found.
-     * This field allows the seconds part of the instant to be queried.
+     * On their own, an instant has insufficient information to allow a local date-time to be obtained.
+     * Only when paired with an offset or time-zone can the local date or time be calculated.
      * <p>
      * This field is strictly defined to have the same meaning in all calendar systems.
      * This is necessary to ensure interoperation between calendars.
@@ -608,24 +613,18 @@ public enum ChronoField implements TemporalField {
         this.displayNameKey = displayNameKey;
     }
 
-    //-----------------------------------------------------------------------
-    @Override
-    public String getName() {
-        return name;
-    }
-
     @Override
     public String getDisplayName(Locale locale) {
         Objects.requireNonNull(locale, "locale");
         if (displayNameKey == null) {
-            return getName();
+            return name;
         }
 
         LocaleResources lr = LocaleProviderAdapter.getResourceBundleBased()
                                     .getLocaleResources(locale);
         ResourceBundle rb = lr.getJavaTimeFormatData();
         String key = "field." + displayNameKey;
-        return rb.containsKey(key) ? rb.getString(key) : getName();
+        return rb.containsKey(key) ? rb.getString(key) : name;
     }
 
     @Override
@@ -748,7 +747,7 @@ public enum ChronoField implements TemporalField {
     //-----------------------------------------------------------------------
     @Override
     public String toString() {
-        return getName();
+        return name;
     }
 
 }

src/share/classes/java/time/temporal/ChronoUnit.java

@@ -57,9 +57,6 @@
 package java.time.temporal;
 
 import java.time.Duration;
-import java.time.chrono.ChronoLocalDate;
-import java.time.chrono.ChronoLocalDateTime;
-import java.time.chrono.ChronoZonedDateTime;
 
 /**
  * A standard set of date periods units.
@@ -200,12 +197,6 @@ public enum ChronoUnit implements TemporalUnit {
         this.duration = estimatedDuration;
     }
 
-    //-----------------------------------------------------------------------
-    @Override
-    public String getName() {
-        return name;
-    }
-
     //-----------------------------------------------------------------------
     /**
      * Gets the estimated duration of this unit in the ISO calendar system.
@@ -233,41 +224,40 @@ public enum ChronoUnit implements TemporalUnit {
      */
     @Override
     public boolean isDurationEstimated() {
-        return isDateUnit();
+        return this.compareTo(DAYS) >= 0;
     }
 
     //-----------------------------------------------------------------------
     /**
      * Checks if this unit is a date unit.
+     * <p>
+     * All units from days to eras inclusive are date-based.
+     * Time-based units and {@code FOREVER} return false.
      *
      * @return true if a date unit, false if a time unit
      */
-    public boolean isDateUnit() {
-        return this.compareTo(DAYS) >= 0;
+    @Override
+    public boolean isDateBased() {
+        return this.compareTo(DAYS) >= 0 && this != FOREVER;
     }
 
     /**
      * Checks if this unit is a time unit.
+     * <p>
+     * All units from nanos to half-days inclusive are time-based.
+     * Date-based units and {@code FOREVER} return false.
      *
      * @return true if a time unit, false if a date unit
      */
-    public boolean isTimeUnit() {
+    @Override
+    public boolean isTimeBased() {
         return this.compareTo(DAYS) < 0;
     }
 
     //-----------------------------------------------------------------------
     @Override
     public boolean isSupportedBy(Temporal temporal) {
-        if (this == FOREVER) {
-            return false;
-        }
-        if (temporal instanceof ChronoLocalDate) {
-            return isDateUnit();
-        }
-        if (temporal instanceof ChronoLocalDateTime || temporal instanceof ChronoZonedDateTime) {
-            return true;
-        }
-        return TemporalUnit.super.isSupportedBy(temporal);
+        return temporal.isSupported(this);
     }
 
     @SuppressWarnings("unchecked")
@@ -279,13 +269,13 @@ public enum ChronoUnit implements TemporalUnit {
     //-----------------------------------------------------------------------
     @Override
     public long between(Temporal temporal1, Temporal temporal2) {
-        return temporal1.periodUntil(temporal2, this);
+        return temporal1.until(temporal2, this);
     }
 
     //-----------------------------------------------------------------------
     @Override
     public String toString() {
-        return getName();
+        return name;
     }
 
 }

src/share/classes/java/time/temporal/JulianFields.java

@@ -66,6 +66,9 @@ import static java.time.temporal.ChronoUnit.DAYS;
 import static java.time.temporal.ChronoUnit.FOREVER;
 
 import java.time.DateTimeException;
+import java.time.ZoneId;
+import java.time.chrono.ChronoLocalDate;
+import java.time.chrono.Chronology;
 import java.time.format.ResolverStyle;
 import java.util.Collections;
 import java.util.Map;
@@ -232,11 +235,6 @@ public final class JulianFields {
         }
 
         //-----------------------------------------------------------------------
-        @Override
-        public String getName() {
-            return name;
-        }
-
         @Override
         public TemporalUnit getBaseUnit() {
             return baseUnit;
@@ -252,6 +250,11 @@ public final class JulianFields {
             return true;
         }
 
+        @Override
+        public boolean isTimeBased() {
+            return false;
+        }
+
         @Override
         public ValueRange range() {
             return range;
@@ -287,15 +290,14 @@ public final class JulianFields {
 
         //-----------------------------------------------------------------------
         @Override
-        public Map<TemporalField, Long> resolve(TemporalAccessor temporal, long value, ResolverStyle resolverStyle) {
-            long epochDay;
+        public ChronoLocalDate resolve(
+                Map<TemporalField, Long> fieldValues, Chronology chronology, ZoneId zone, ResolverStyle resolverStyle) {
+            long value = fieldValues.remove(this);
             if (resolverStyle == ResolverStyle.LENIENT) {
-                epochDay = Math.subtractExact(value, offset);
-            } else {
-                range().checkValidValue(value, this);
-                epochDay = value - offset;
+                return chronology.dateEpochDay(Math.subtractExact(value, offset));
             }
-            return Collections.<TemporalField, Long>singletonMap(EPOCH_DAY, epochDay);
+            range().checkValidValue(value, this);
+            return chronology.dateEpochDay(value - offset);
         }
 
         //-----------------------------------------------------------------------

src/share/classes/java/time/temporal/Temporal.java

@@ -62,7 +62,6 @@
 package java.time.temporal;
 
 import java.time.DateTimeException;
-import java.time.ZoneId;
 
 /**
  * Framework-level interface defining read-write access to a temporal object,
@@ -81,7 +80,8 @@ import java.time.ZoneId;
  * See {@link ChronoField} for the standard set of fields.
  * <p>
  * Two pieces of date/time information cannot be represented by numbers,
- * the {@linkplain java.time.chrono.Chronology chronology} and the {@linkplain ZoneId time-zone}.
+ * the {@linkplain java.time.chrono.Chronology chronology} and the
+ * {@linkplain java.time.ZoneId time-zone}.
  * These can be accessed via {@link #query(TemporalQuery) queries} using
  * the static methods defined on {@link TemporalQuery}.
  * <p>
@@ -128,6 +128,29 @@ import java.time.ZoneId;
  */
 public interface Temporal extends TemporalAccessor {
 
+    /**
+     * Checks if the specified unit is supported.
+     * <p>
+     * This checks if the specified unit can be added to, or subtracted from, this date-time.
+     * If false, then calling the {@link #plus(long, TemporalUnit)} and
+     * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
+     *
+     * @implSpec
+     * Implementations must check and handle all units defined in {@link ChronoUnit}.
+     * If the unit is supported, then true must be returned, otherwise false must be returned.
+     * <p>
+     * If the field is not a {@code ChronoUnit}, then the result of this method
+     * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
+     * passing {@code this} as the argument.
+     * <p>
+     * Implementations must ensure that no observable state is altered when this
+     * read-only method is invoked.
+     *
+     * @param unit  the unit to check, null returns false
+     * @return true if the unit can be added/subtracted, false if not
+     */
+    boolean isSupported(TemporalUnit unit);
+
     /**
      * Returns an adjusted object of the same type as this object with the adjustment made.
      * <p>
@@ -352,7 +375,7 @@ public interface Temporal extends TemporalAccessor {
      * The start and end points are {@code this} and the specified temporal.
      * The result will be negative if the end is before the start.
      * For example, the period in hours between two temporal objects can be
-     * calculated using {@code startTime.periodUntil(endTime, HOURS)}.
+     * calculated using {@code startTime.until(endTime, HOURS)}.
      * <p>
      * The calculation returns a whole number, representing the number of
      * complete units between the two temporals.
@@ -364,7 +387,7 @@ public interface Temporal extends TemporalAccessor {
      * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
      * <pre>
      *   // these two lines are equivalent
-     *   temporal = start.periodUntil(end, unit);
+     *   temporal = start.until(end, unit);
      *   temporal = unit.between(start, end);
      * </pre>
      * The choice should be made based on which makes the code more readable.
@@ -372,7 +395,7 @@ public interface Temporal extends TemporalAccessor {
      * For example, this method allows the number of days between two dates to
      * be calculated:
      * <pre>
-     *  long daysBetween = start.periodUntil(end, DAYS);
+     *  long daysBetween = start.until(end, DAYS);
      *  // or alternatively
      *  long daysBetween = DAYS.between(start, end);
      * </pre>
@@ -399,7 +422,8 @@ public interface Temporal extends TemporalAccessor {
      *  return unit.between(this, endTemporal);
      * </pre>
      * <p>
-     * Neither this object, nor the specified temporal, may be altered.
+     * Implementations must ensure that no observable state is altered when this
+     * read-only method is invoked.
      *
      * @param endTemporal  the end temporal, of the same type as this object, not null
      * @param unit  the unit to measure the amount in, not null
@@ -410,6 +434,6 @@ public interface Temporal extends TemporalAccessor {
      * @throws UnsupportedTemporalTypeException if the unit is not supported
      * @throws ArithmeticException if numeric overflow occurs
      */
-    long periodUntil(Temporal endTemporal, TemporalUnit unit);
+    long until(Temporal endTemporal, TemporalUnit unit);
 
 }

src/share/classes/java/time/temporal/ValueRange.java

@@ -331,7 +331,7 @@ public final class ValueRange implements Serializable {
 
     private String genInvalidFieldMessage(TemporalField field, long value) {
         if (field != null) {
-            return "Invalid value for " + field.getName() + " (valid values " + this + "): " + value;
+            return "Invalid value for " + field + " (valid values " + this + "): " + value;
         } else {
             return "Invalid value (valid values " + this + "): " + value;
         }

test/java/time/tck/java/time/MockSimplePeriod.java

@@ -176,7 +176,7 @@ public final class MockSimplePeriod
 
     @Override
     public String toString() {
-        return amount + " " + unit.getName();
+        return amount + " " + unit;
     }
 
 }

test/java/time/tck/java/time/TCKClock_Fixed.java

@@ -91,6 +91,7 @@ public class TCKClock_Fixed extends AbstractTCKTest {
         Clock test = Clock.fixed(INSTANT, PARIS);
         assertEquals(test.instant(), INSTANT);
         assertEquals(test.getZone(), PARIS);
+   assertEquals(test.instant().getEpochSecond()*1000, test.millis());
     }
 
     @Test(expectedExceptions = NullPointerException.class)

test/java/time/tck/java/time/chrono/TCKHijrahEra.java

@@ -85,6 +85,8 @@ public class TCKHijrahEra {
     @Test(dataProvider="HijrahEras")
     public void test_valueOf(HijrahEra era , String eraName, int eraValue) {
         assertEquals(era.getValue(), eraValue);
+
+        assertEquals(HijrahChronology.INSTANCE.eraOf(eraValue), era);
         assertEquals(HijrahEra.of(eraValue), era);
         assertEquals(HijrahEra.valueOf(eraName), era);
     }

test/java/time/tck/java/time/chrono/TCKJapaneseEra.java

@@ -81,7 +81,6 @@ public class TCKJapaneseEra {
                     {JapaneseEra.SHOWA, "Showa", 1},
                     {JapaneseEra.TAISHO, "Taisho", 0},
                     {JapaneseEra.MEIJI, "Meiji", -1},
-                    {JapaneseEra.SEIREKI, "Seireki", -999},
         };
     }
 
@@ -112,8 +111,8 @@ public class TCKJapaneseEra {
     public void test_range() {
         // eras may be added after release
         for (JapaneseEra era : JapaneseEra.values()) {
-            assertEquals(era.range(ERA).getMinimum(), -999);
-            assertEquals(era.range(ERA).getLargestMinimum(), -999);
+            assertEquals(era.range(ERA).getMinimum(), -1);
+            assertEquals(era.range(ERA).getLargestMinimum(), -1);
             assertEquals(era.range(ERA).getSmallestMaximum(), era.range(ERA).getMaximum());
             assertEquals(era.range(ERA).getMaximum() >= 2, true);
         }

test/java/time/tck/java/time/format/TCKTextStyle.java

@@ -91,4 +91,14 @@ public class TCKTextStyle {
         assertTrue(!TextStyle.NARROW.isStandalone());
     }
 
+    //-----------------------------------------------------------------------
+    // valueOf()
+    //-----------------------------------------------------------------------
+    @Test
+    public void test_valueOf() {
+        for (TextStyle style : TextStyle.values()) {
+            assertEquals(TextStyle.valueOf(style.name()), style);
+        }
+    }
+
 }