7088913: Add compatible static hashCode(primitive) to primitive wrapper classes

Summary: Adds static utility methods to each primitive wrapper class to allow calculation of a hashCode value from an unboxed primitive.
Reviewed-by: darcy, smarks, dholmes

src/share/classes/java/lang/Boolean.java

@@ -196,7 +196,20 @@ public final class Boolean implements java.io.Serializable,
      * {@code true}; returns the integer {@code 1237} if this
      * object represents {@code false}.
      */
+    @Override
     public int hashCode() {
+        return Boolean.hashCode(value);
+    }
+
+    /**
+     * Returns a hash code for a {@code boolean} value; compatible with
+     * {@code Boolean.hashCode()}.
+     *
+     * @since 1.8
+     *
+     * @return a hash code value for a {@code boolean} value.
+     */
+    public static int hashCode(boolean value) {
         return value ? 1231 : 1237;
     }
 

src/share/classes/java/lang/Byte.java

@@ -389,7 +389,20 @@ public final class Byte extends Number implements Comparable<Byte> {
      *
      * @return a hash code value for this {@code Byte}
      */
+    @Override
     public int hashCode() {
+        return Byte.hashCode(value);
+    }
+
+    /**
+     * Returns a hash code for a {@code byte} value; compatible with
+     * {@code Byte.hashCode()}.
+     *
+     * @since 1.8
+     *
+     * @return a hash code value for a {@code byte} value.
+     */
+    public static int hashCode(byte value) {
         return (int)value;
     }
 

src/share/classes/java/lang/Character.java

@@ -4588,7 +4588,20 @@ class Character implements java.io.Serializable, Comparable<Character> {
      *
      * @return a hash code value for this {@code Character}
      */
+    @Override
     public int hashCode() {
+        return Character.hashCode(value);
+    }
+
+    /**
+     * Returns a hash code for a {@code char} value; compatible with
+     * {@code Character.hashCode()}.
+     *
+     * @since 1.8
+     *
+     * @return a hash code value for a {@code char} value.
+     */
+    public static int hashCode(char value) {
         return (int)value;
     }
 

src/share/classes/java/lang/Double.java

@@ -740,7 +740,20 @@ public final class Double extends Number implements Comparable<Double> {
      *
      * @return  a {@code hash code} value for this object.
      */
+    @Override
     public int hashCode() {
+        return Double.hashCode(value);
+    }
+
+    /**
+     * Returns a hash code for a {@code double} value; compatible with
+     * {@code Double.hashCode()}.
+     *
+     * @since 1.8
+     *
+     * @return a hash code value for a {@code double} value.
+     */
+    public static int hashCode(double value) {
         long bits = doubleToLongBits(value);
         return (int)(bits ^ (bits >>> 32));
     }

src/share/classes/java/lang/Float.java

@@ -648,7 +648,20 @@ public final class Float extends Number implements Comparable<Float> {
      *
      * @return a hash code value for this object.
      */
+    @Override
     public int hashCode() {
+        return Float.hashCode(value);
+    }
+
+    /**
+     * Returns a hash code for a {@code float} value; compatible with
+     * {@code Float.hashCode()}.
+     *
+     * @since 1.8
+     *
+     * @return a hash code value for a {@code float} value.
+     */
+    public static int hashCode(float value) {
         return floatToIntBits(value);
     }
 

src/share/classes/java/lang/Integer.java

@@ -918,7 +918,20 @@ public final class Integer extends Number implements Comparable<Integer> {
      *          primitive {@code int} value represented by this
      *          {@code Integer} object.
      */
+    @Override
     public int hashCode() {
+        return Integer.hashCode(value);
+    }
+
+    /**
+     * Returns a hash code for a {@code int} value; compatible with
+     * {@code Integer.hashCode()}.
+     *
+     * @since 1.8
+     *
+     * @return a hash code value for a {@code int} value.
+     */
+    public static int hashCode(int value) {
         return value;
     }
 

src/share/classes/java/lang/Long.java

@@ -1021,7 +1021,20 @@ public final class Long extends Number implements Comparable<Long> {
      *
      * @return  a hash code value for this object.
      */
+    @Override
     public int hashCode() {
+        return Long.hashCode(value);
+    }
+
+    /**
+     * Returns a hash code for a {@code long} value; compatible with
+     * {@code Long.hashCode()}.
+     *
+     * @since 1.8
+     *
+     * @return a hash code value for a {@code long} value.
+     */
+    public static int hashCode(long value) {
         return (int)(value ^ (value >>> 32));
     }
 

src/share/classes/java/lang/Short.java

@@ -394,7 +394,20 @@ public final class Short extends Number implements Comparable<Short> {
      *
      * @return a hash code value for this {@code Short}
      */
+    @Override
     public int hashCode() {
+        return Short.hashCode(value);
+    }
+
+    /**
+     * Returns a hash code for a {@code short} value; compatible with
+     * {@code Short.hashCode()}.
+     *
+     * @since 1.8
+     *
+     * @return a hash code value for a {@code short} value.
+     */
+    public static int hashCode(short value) {
         return (int)value;
     }
 

test/java/lang/HashCode.java

@@ -23,18 +23,20 @@
 
 /*
  * @test
- * @bug 4245470
+ * @bug 4245470 7088913
  * @summary Test the primitive wrappers hashCode()
  */
 
+import java.util.Objects;
 import java.util.Random;
 
 public class HashCode {
 
     final Random rnd = new Random();
 
-    void test(String args[]) throws Exception {
-        int[] ints = {
+    void testOrdinals(String args[]) throws Exception {
+        long[] longs = {
+            Long.MIN_VALUE,
             Integer.MIN_VALUE,
             Short.MIN_VALUE,
             Character.MIN_VALUE,
@@ -44,20 +46,73 @@ public class HashCode {
             Character.MAX_VALUE,
             Short.MAX_VALUE,
             Integer.MAX_VALUE,
+            Long.MAX_VALUE,
             rnd.nextInt(),
         };
 
-        for (int x : ints) {
+        for (long x : longs) {
             check(    new Long(x).hashCode() == (int)((long)x ^ (long)x>>>32));
             check(Long.valueOf(x).hashCode() == (int)((long)x ^ (long)x>>>32));
-            check(    new Integer(x).hashCode() == x);
-            check(Integer.valueOf(x).hashCode() == x);
+            check(  (new Long(x)).hashCode() == Long.hashCode(x));
+            check(    new Integer((int)x).hashCode() == (int) x);
+            check(Integer.valueOf((int)x).hashCode() == (int) x);
+            check(  (new Integer((int)x)).hashCode() == Integer.hashCode((int)x));
             check(    new Short((short)x).hashCode() == (short) x);
             check(Short.valueOf((short)x).hashCode() == (short) x);
+            check(         (new Short((short)x)).hashCode() == Short.hashCode((short)x));
             check(    new Character((char) x).hashCode() == (char) x);
             check(Character.valueOf((char) x).hashCode() == (char) x);
+            check(         (new Character((char)x)).hashCode() == Character.hashCode((char)x));
             check(    new Byte((byte) x).hashCode() == (byte) x);
             check(Byte.valueOf((byte) x).hashCode() == (byte) x);
+            check(         (new Byte((byte)x)).hashCode() == Byte.hashCode((byte)x));
+        }
+    }
+
+    void testBoolean() {
+        check( Boolean.FALSE.hashCode() == 1237);
+        check( Boolean.TRUE.hashCode() == 1231);
+        check( Boolean.valueOf(false).hashCode() == 1237);
+        check( Boolean.valueOf(true).hashCode() == 1231);
+        check( (new Boolean(false)).hashCode() == 1237);
+        check( (new Boolean(true)).hashCode() == 1231);
+        check( Boolean.hashCode(false) == 1237);
+        check( Boolean.hashCode(true) == 1231);
+    }
+
+    void testFloat() {
+        float[] floats = {
+            Float.NaN,
+            Float.NEGATIVE_INFINITY,
+               -1f,
+               0f,
+               1f,
+               Float.POSITIVE_INFINITY
+        };
+
+        for(float f : floats) {
+            check( Float.hashCode(f) == Float.floatToIntBits(f));
+            check( Float.valueOf(f).hashCode() == Float.floatToIntBits(f));
+            check( (new Float(f)).hashCode() == Float.floatToIntBits(f));
+        }
+    }
+
+    void testDouble() {
+        double[] doubles = {
+            Double.NaN,
+            Double.NEGATIVE_INFINITY,
+               -1f,
+               0f,
+               1f,
+               Double.POSITIVE_INFINITY
+        };
+
+        for(double d : doubles) {
+            long bits = Double.doubleToLongBits(d);
+            int bitsHash = (int)(bits^(bits>>>32));
+            check( Double.hashCode(d) == bitsHash);
+            check( Double.valueOf(d).hashCode() == bitsHash);
+            check( (new Double(d)).hashCode() == bitsHash);
         }
     }
 
@@ -69,12 +124,16 @@ public class HashCode {
     void unexpected(Throwable t) {failed++; t.printStackTrace();}
     void check(boolean cond) {if (cond) pass(); else fail();}
     void equal(Object x, Object y) {
-        if (x == null ? y == null : x.equals(y)) pass();
+        if (Objects.equals(x,y)) pass();
         else fail(x + " not equal to " + y);}
     public static void main(String[] args) throws Throwable {
         new HashCode().instanceMain(args);}
     public void instanceMain(String[] args) throws Throwable {
-        try {test(args);} catch (Throwable t) {unexpected(t);}
+        try { testOrdinals(args);
+              testBoolean();
+                testFloat();
+                testDouble();
+        } catch (Throwable t) {unexpected(t);}
         System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
         if (failed > 0) throw new AssertionError("Some tests failed");}
 }