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dragonwell8_jdk
提交 ad59a26e 编写于 作者: C chegar
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上级 29a714c1 6019b1d8
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src/share/classes/java/util/Collections.java
浏览文件 @ ad59a26e
...@@ -28,6 +28,9 @@ import java.io.Serializable; ...@@ -28,6 +28,9 @@ import java.io.Serializable;
import java.io.ObjectOutputStream; import java.io.ObjectOutputStream;
import java.io.IOException; import java.io.IOException;
import java.lang.reflect.Array; import java.lang.reflect.Array;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import java.util.function.Function;
/** /**
* This class consists exclusively of static methods that operate on or return * This class consists exclusively of static methods that operate on or return
...@@ -264,8 +267,7 @@ public class Collections { ...@@ -264,8 +267,7 @@ public class Collections {
} }
private static <T> private static <T>
int indexedBinarySearch(List<? extends Comparable<? super T>> list, T key) int indexedBinarySearch(List<? extends Comparable<? super T>> list, T key) {
{
int low = 0; int low = 0;
int high = list.size()-1; int high = list.size()-1;
...@@ -441,21 +443,21 @@ public class Collections { ...@@ -441,21 +443,21 @@ public class Collections {
/** /**
* Randomly permutes the specified list using a default source of * Randomly permutes the specified list using a default source of
* randomness. All permutations occur with approximately equal * randomness. All permutations occur with approximately equal
* likelihood.<p> * likelihood.
* *
* The hedge "approximately" is used in the foregoing description because * <p>The hedge "approximately" is used in the foregoing description because
* default source of randomness is only approximately an unbiased source * default source of randomness is only approximately an unbiased source
* of independently chosen bits. If it were a perfect source of randomly * of independently chosen bits. If it were a perfect source of randomly
* chosen bits, then the algorithm would choose permutations with perfect * chosen bits, then the algorithm would choose permutations with perfect
* uniformity.<p> * uniformity.
* *
* This implementation traverses the list backwards, from the last element * <p>This implementation traverses the list backwards, from the last
* up to the second, repeatedly swapping a randomly selected element into * element up to the second, repeatedly swapping a randomly selected element
* the "current position". Elements are randomly selected from the * into the "current position". Elements are randomly selected from the
* portion of the list that runs from the first element to the current * portion of the list that runs from the first element to the current
* position, inclusive.<p> * position, inclusive.
* *
* This method runs in linear time. If the specified list does not * <p>This method runs in linear time. If the specified list does not
* implement the {@link RandomAccess} interface and is large, this * implement the {@link RandomAccess} interface and is large, this
* implementation dumps the specified list into an array before shuffling * implementation dumps the specified list into an array before shuffling
* it, and dumps the shuffled array back into the list. This avoids the * it, and dumps the shuffled array back into the list. This avoids the
...@@ -469,9 +471,10 @@ public class Collections { ...@@ -469,9 +471,10 @@ public class Collections {
public static void shuffle(List<?> list) { public static void shuffle(List<?> list) {
Random rnd = r; Random rnd = r;
if (rnd == null) if (rnd == null)
r = rnd = new Random(); r = rnd = new Random(); // harmless race.
shuffle(list, rnd); shuffle(list, rnd);
} }
private static Random r; private static Random r;
/** /**
...@@ -1391,6 +1394,67 @@ public class Collections { ...@@ -1391,6 +1394,67 @@ public class Collections {
public int hashCode() {return m.hashCode();} public int hashCode() {return m.hashCode();}
public String toString() {return m.toString();} public String toString() {return m.toString();}
// Override default methods in Map
@Override
@SuppressWarnings("unchecked")
public V getOrDefault(Object k, V defaultValue) {
// Safe cast as we don't change the value
return ((Map<K, V>)m).getOrDefault(k, defaultValue);
}
@Override
public void forEach(BiConsumer<? super K, ? super V> action) {
m.forEach(action);
}
@Override
public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
throw new UnsupportedOperationException();
}
@Override
public V putIfAbsent(K key, V value) {
throw new UnsupportedOperationException();
}
@Override
public boolean remove(Object key, Object value) {
throw new UnsupportedOperationException();
}
@Override
public boolean replace(K key, V oldValue, V newValue) {
throw new UnsupportedOperationException();
}
@Override
public V replace(K key, V value) {
throw new UnsupportedOperationException();
}
@Override
public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
throw new UnsupportedOperationException();
}
@Override
public V computeIfPresent(K key,
BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
throw new UnsupportedOperationException();
}
@Override
public V compute(K key,
BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
throw new UnsupportedOperationException();
}
@Override
public V merge(K key, V value,
BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
throw new UnsupportedOperationException();
}
/** /**
* We need this class in addition to UnmodifiableSet as * We need this class in addition to UnmodifiableSet as
* Map.Entries themselves permit modification of the backing Map * Map.Entries themselves permit modification of the backing Map
...@@ -1590,9 +1654,9 @@ public class Collections { ...@@ -1590,9 +1654,9 @@ public class Collections {
* </pre> * </pre>
* Failure to follow this advice may result in non-deterministic behavior. * Failure to follow this advice may result in non-deterministic behavior.
* *
* <p>The returned collection does <i>not</i> pass the <tt>hashCode</tt> * <p>The returned collection does <i>not</i> pass the {@code hashCode}
* and <tt>equals</tt> operations through to the backing collection, but * and {@code equals} operations through to the backing collection, but
* relies on <tt>Object</tt>'s equals and hashCode methods. This is * relies on {@code Object}'s equals and hashCode methods. This is
* necessary to preserve the contracts of these operations in the case * necessary to preserve the contracts of these operations in the case
* that the backing collection is a set or a list.<p> * that the backing collection is a set or a list.<p>
* *
...@@ -2107,6 +2171,57 @@ public class Collections { ...@@ -2107,6 +2171,57 @@ public class Collections {
public String toString() { public String toString() {
synchronized (mutex) {return m.toString();} synchronized (mutex) {return m.toString();}
} }
// Override default methods in Map
@Override
public V getOrDefault(Object k, V defaultValue) {
synchronized (mutex) {return m.getOrDefault(k, defaultValue);}
}
@Override
public void forEach(BiConsumer<? super K, ? super V> action) {
synchronized (mutex) {m.forEach(action);}
}
@Override
public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
synchronized (mutex) {m.replaceAll(function);}
}
@Override
public V putIfAbsent(K key, V value) {
synchronized (mutex) {return m.putIfAbsent(key, value);}
}
@Override
public boolean remove(Object key, Object value) {
synchronized (mutex) {return m.remove(key, value);}
}
@Override
public boolean replace(K key, V oldValue, V newValue) {
synchronized (mutex) {return m.replace(key, oldValue, newValue);}
}
@Override
public V replace(K key, V value) {
synchronized (mutex) {return m.replace(key, value);}
}
@Override
public V computeIfAbsent(K key,
Function<? super K, ? extends V> mappingFunction) {
synchronized (mutex) {return m.computeIfAbsent(key, mappingFunction);}
}
@Override
public V computeIfPresent(K key,
BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
synchronized (mutex) {return m.computeIfPresent(key, remappingFunction);}
}
@Override
public V compute(K key,
BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
synchronized (mutex) {return m.compute(key, remappingFunction);}
}
@Override
public V merge(K key, V value,
BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
synchronized (mutex) {return m.merge(key, value, remappingFunction);}
}
private void writeObject(ObjectOutputStream s) throws IOException { private void writeObject(ObjectOutputStream s) throws IOException {
synchronized (mutex) {s.defaultWriteObject();} synchronized (mutex) {s.defaultWriteObject();}
} }
...@@ -2326,6 +2441,8 @@ public class Collections { ...@@ -2326,6 +2441,8 @@ public class Collections {
} }
public Iterator<E> iterator() { public Iterator<E> iterator() {
// JDK-6363904 - unwrapped iterator could be typecast to
// ListIterator with unsafe set()
final Iterator<E> it = c.iterator(); final Iterator<E> it = c.iterator();
return new Iterator<E>() { return new Iterator<E>() {
public boolean hasNext() { return it.hasNext(); } public boolean hasNext() { return it.hasNext(); }
...@@ -2652,7 +2769,7 @@ public class Collections { ...@@ -2652,7 +2769,7 @@ public class Collections {
public List<E> subList(int fromIndex, int toIndex) { public List<E> subList(int fromIndex, int toIndex) {
return new CheckedRandomAccessList<>( return new CheckedRandomAccessList<>(
list.subList(fromIndex, toIndex), type); list.subList(fromIndex, toIndex), type);
} }
} }
...@@ -2717,14 +2834,24 @@ public class Collections { ...@@ -2717,14 +2834,24 @@ public class Collections {
throw new ClassCastException(badValueMsg(value)); throw new ClassCastException(badValueMsg(value));
} }
private BiFunction<? super K, ? super V, ? extends V> typeCheck(
BiFunction<? super K, ? super V, ? extends V> func) {
Objects.requireNonNull(func);
return (k, v) -> {
V newValue = func.apply(k, v);
typeCheck(k, newValue);
return newValue;
};
}
private String badKeyMsg(Object key) { private String badKeyMsg(Object key) {
return "Attempt to insert " + key.getClass() + return "Attempt to insert " + key.getClass() +
" key into map with key type " + keyType; " key into map with key type " + keyType;
} }
private String badValueMsg(Object value) { private String badValueMsg(Object value) {
return "Attempt to insert " + value.getClass() + return "Attempt to insert " + value.getClass() +
" value into map with value type " + valueType; " value into map with value type " + valueType;
} }
CheckedMap(Map<K, V> m, Class<K> keyType, Class<V> valueType) { CheckedMap(Map<K, V> m, Class<K> keyType, Class<V> valueType) {
...@@ -2768,7 +2895,7 @@ public class Collections { ...@@ -2768,7 +2895,7 @@ public class Collections {
Object v = e.getValue(); Object v = e.getValue();
typeCheck(k, v); typeCheck(k, v);
checked.add( checked.add(
new AbstractMap.SimpleImmutableEntry<>((K) k, (V) v)); new AbstractMap.SimpleImmutableEntry<>((K)k, (V)v));
} }
for (Map.Entry<K,V> e : checked) for (Map.Entry<K,V> e : checked)
m.put(e.getKey(), e.getValue()); m.put(e.getKey(), e.getValue());
...@@ -2782,6 +2909,74 @@ public class Collections { ...@@ -2782,6 +2909,74 @@ public class Collections {
return entrySet; return entrySet;
} }
// Override default methods in Map
@Override
public void forEach(BiConsumer<? super K, ? super V> action) {
m.forEach(action);
}
@Override
public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
m.replaceAll(typeCheck(function));
}
@Override
public V putIfAbsent(K key, V value) {
typeCheck(key, value);
return m.putIfAbsent(key, value);
}
@Override
public boolean remove(Object key, Object value) {
return m.remove(key, value);
}
@Override
public boolean replace(K key, V oldValue, V newValue) {
typeCheck(key, newValue);
return m.replace(key, oldValue, newValue);
}
@Override
public V replace(K key, V value) {
typeCheck(key, value);
return m.replace(key, value);
}
@Override
public V computeIfAbsent(K key,
Function<? super K, ? extends V> mappingFunction) {
Objects.requireNonNull(mappingFunction);
return m.computeIfAbsent(key, k -> {
V value = mappingFunction.apply(k);
typeCheck(k, value);
return value;
});
}
@Override
public V computeIfPresent(K key,
BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
return m.computeIfPresent(key, typeCheck(remappingFunction));
}
@Override
public V compute(K key,
BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
return m.compute(key, typeCheck(remappingFunction));
}
@Override
public V merge(K key, V value,
BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
Objects.requireNonNull(remappingFunction);
return m.merge(key, value, (v1, v2) -> {
V newValue = remappingFunction.apply(v1, v2);
typeCheck(null, newValue);
return newValue;
});
}
/** /**
* We need this class in addition to CheckedSet as Map.Entry permits * We need this class in addition to CheckedSet as Map.Entry permits
* modification of the backing Map via the setValue operation. This * modification of the backing Map via the setValue operation. This
...@@ -3456,6 +3651,67 @@ public class Collections { ...@@ -3456,6 +3651,67 @@ public class Collections {
public int hashCode() {return 0;} public int hashCode() {return 0;}
// Override default methods in Map
@Override
@SuppressWarnings("unchecked")
public V getOrDefault(Object k, V defaultValue) {
return defaultValue;
}
@Override
public void forEach(BiConsumer<? super K, ? super V> action) {
Objects.requireNonNull(action);
}
@Override
public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
Objects.requireNonNull(function);
}
@Override
public V putIfAbsent(K key, V value) {
throw new UnsupportedOperationException();
}
@Override
public boolean remove(Object key, Object value) {
throw new UnsupportedOperationException();
}
@Override
public boolean replace(K key, V oldValue, V newValue) {
throw new UnsupportedOperationException();
}
@Override
public V replace(K key, V value) {
throw new UnsupportedOperationException();
}
@Override
public V computeIfAbsent(K key,
Function<? super K, ? extends V> mappingFunction) {
throw new UnsupportedOperationException();
}
@Override
public V computeIfPresent(K key,
BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
throw new UnsupportedOperationException();
}
@Override
public V compute(K key,
BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
throw new UnsupportedOperationException();
}
@Override
public V merge(K key, V value,
BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
throw new UnsupportedOperationException();
}
// Preserves singleton property // Preserves singleton property
private Object readResolve() { private Object readResolve() {
return EMPTY_MAP; return EMPTY_MAP;
...@@ -3619,6 +3875,65 @@ public class Collections { ...@@ -3619,6 +3875,65 @@ public class Collections {
return values; return values;
} }
// Override default methods in Map
@Override
public V getOrDefault(Object key, V defaultValue) {
return eq(key, k) ? v : defaultValue;
}
@Override
public void forEach(BiConsumer<? super K, ? super V> action) {
action.accept(k, v);
}
@Override
public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
throw new UnsupportedOperationException();
}
@Override
public V putIfAbsent(K key, V value) {
throw new UnsupportedOperationException();
}
@Override
public boolean remove(Object key, Object value) {
throw new UnsupportedOperationException();
}
@Override
public boolean replace(K key, V oldValue, V newValue) {
throw new UnsupportedOperationException();
}
@Override
public V replace(K key, V value) {
throw new UnsupportedOperationException();
}
@Override
public V computeIfAbsent(K key,
Function<? super K, ? extends V> mappingFunction) {
throw new UnsupportedOperationException();
}
@Override
public V computeIfPresent(K key,
BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
throw new UnsupportedOperationException();
}
@Override
public V compute(K key,
BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
throw new UnsupportedOperationException();
}
@Override
public V merge(K key, V value,
BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
throw new UnsupportedOperationException();
}
} }
// Miscellaneous // Miscellaneous
......
src/share/classes/java/util/HashMap.java
浏览文件 @ ad59a26e
/* /*
* Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
* *
* This code is free software; you can redistribute it and/or modify it * This code is free software; you can redistribute it and/or modify it
...@@ -24,7 +24,11 @@ ...@@ -24,7 +24,11 @@
*/ */
package java.util; package java.util;
import java.io.*; import java.io.*;
import java.util.function.Consumer;
import java.util.function.BiFunction;
import java.util.function.Function;
/** /**
* Hash table based implementation of the <tt>Map</tt> interface. This * Hash table based implementation of the <tt>Map</tt> interface. This
...@@ -376,6 +380,13 @@ public class HashMap<K,V> ...@@ -376,6 +380,13 @@ public class HashMap<K,V>
return null == entry ? null : entry.getValue(); return null == entry ? null : entry.getValue();
} }
@Override
public V getOrDefault(Object key, V defaultValue) {
Entry<K,V> entry = getEntry(key);
return (entry == null) ? defaultValue : entry.getValue();
}
/** /**
* Returns <tt>true</tt> if this map contains a mapping for the * Returns <tt>true</tt> if this map contains a mapping for the
* specified key. * specified key.
...@@ -603,6 +614,261 @@ public class HashMap<K,V> ...@@ -603,6 +614,261 @@ public class HashMap<K,V>
return (e == null ? null : e.value); return (e == null ? null : e.value);
} }
// optimized implementations of default methods in Map
@Override
public V putIfAbsent(K key, V value) {
if (table == EMPTY_TABLE) {
inflateTable(threshold);
}
int hash = (key == null) ? 0 : hash(key);
int i = indexFor(hash, table.length);
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)table[i];
for(; e != null; e = e.next) {
if (e.hash == hash && Objects.equals(e.key, key)) {
if(e.value != null) {
return e.value;
}
e.value = value;
modCount++;
e.recordAccess(this);
return null;
}
}
modCount++;
addEntry(hash, key, value, i);
return null;
}
@Override
public boolean remove(Object key, Object value) {
if (isEmpty()) {
return false;
}
int hash = (key == null) ? 0 : hash(key);
int i = indexFor(hash, table.length);
@SuppressWarnings("unchecked")
Entry<K,V> prev = (Entry<K,V>)table[i];
Entry<K,V> e = prev;
while (e != null) {
Entry<K,V> next = e.next;
if (e.hash == hash && Objects.equals(e.key, key)) {
if (!Objects.equals(e.value, value)) {
return false;
}
modCount++;
size--;
if (prev == e)
table[i] = next;
else
prev.next = next;
e.recordRemoval(this);
return true;
}
prev = e;
e = next;
}
return false;
}
@Override
public boolean replace(K key, V oldValue, V newValue) {
if (isEmpty()) {
return false;
}
int hash = (key == null) ? 0 : hash(key);
int i = indexFor(hash, table.length);
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)table[i];
for (; e != null; e = e.next) {
if (e.hash == hash && Objects.equals(e.key, key) && Objects.equals(e.value, oldValue)) {
e.value = newValue;
e.recordAccess(this);
return true;
}
}
return false;
}
@Override
public V replace(K key, V value) {
if (isEmpty()) {
return null;
}
int hash = (key == null) ? 0 : hash(key);
int i = indexFor(hash, table.length);
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)table[i];
for (; e != null; e = e.next) {
if (e.hash == hash && Objects.equals(e.key, key)) {
V oldValue = e.value;
e.value = value;
e.recordAccess(this);
return oldValue;
}
}
return null;
}
@Override
public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
if (table == EMPTY_TABLE) {
inflateTable(threshold);
}
int hash = (key == null) ? 0 : hash(key);
int i = indexFor(hash, table.length);
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)table[i];
for (; e != null; e = e.next) {
if (e.hash == hash && Objects.equals(e.key, key)) {
V oldValue = e.value;
return oldValue == null ? (e.value = mappingFunction.apply(key)) : oldValue;
}
}
V newValue = mappingFunction.apply(key);
if (newValue != null) {
modCount++;
addEntry(hash, key, newValue, i);
}
return newValue;
}
@Override
public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
if (isEmpty()) {
return null;
}
int hash = (key == null) ? 0 : hash(key);
int i = indexFor(hash, table.length);
@SuppressWarnings("unchecked")
Entry<K,V> prev = (Entry<K,V>)table[i];
Entry<K,V> e = prev;
while (e != null) {
Entry<K,V> next = e.next;
if (e.hash == hash && Objects.equals(e.key, key)) {
V oldValue = e.value;
if (oldValue == null)
break;
V newValue = remappingFunction.apply(key, oldValue);
modCount++;
if (newValue == null) {
size--;
if (prev == e)
table[i] = next;
else
prev.next = next;
e.recordRemoval(this);
} else {
e.value = newValue;
e.recordAccess(this);
}
return newValue;
}
prev = e;
e = next;
}
return null;
}
@Override
public V compute(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
if (table == EMPTY_TABLE) {
inflateTable(threshold);
}
int hash = (key == null) ? 0 : hash(key);
int i = indexFor(hash, table.length);
@SuppressWarnings("unchecked")
Entry<K,V> prev = (Entry<K,V>)table[i];
Entry<K,V> e = prev;
while (e != null) {
Entry<K,V> next = e.next;
if (e.hash == hash && Objects.equals(e.key, key)) {
V oldValue = e.value;
V newValue = remappingFunction.apply(key, oldValue);
if (newValue != oldValue) {
modCount++;
if (newValue == null) {
size--;
if (prev == e)
table[i] = next;
else
prev.next = next;
e.recordRemoval(this);
} else {
e.value = newValue;
e.recordAccess(this);
}
}
return newValue;
}
prev = e;
e = next;
}
V newValue = remappingFunction.apply(key, null);
if (newValue != null) {
modCount++;
addEntry(hash, key, newValue, i);
}
return newValue;
}
@Override
public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
if (table == EMPTY_TABLE) {
inflateTable(threshold);
}
int hash = (key == null) ? 0 : hash(key);
int i = indexFor(hash, table.length);
@SuppressWarnings("unchecked")
Entry<K,V> prev = (Entry<K,V>)table[i];
Entry<K,V> e = prev;
while (e != null) {
Entry<K,V> next = e.next;
if (e.hash == hash && Objects.equals(e.key, key)) {
V oldValue = e.value;
V newValue = remappingFunction.apply(oldValue, value);
modCount++;
if (newValue == null) {
size--;
if (prev == e)
table[i] = next;
else
prev.next = next;
e.recordRemoval(this);
} else {
e.value = newValue;
e.recordAccess(this);
}
return newValue;
}
prev = e;
e = next;
}
if (value != null) {
modCount++;
addEntry(hash, key, value, i);
}
return value;
}
// end of optimized implementations of default methods in Map
/** /**
* Removes and returns the entry associated with the specified key * Removes and returns the entry associated with the specified key
* in the HashMap. Returns null if the HashMap contains no mapping * in the HashMap. Returns null if the HashMap contains no mapping
...@@ -697,8 +963,8 @@ public class HashMap<K,V> ...@@ -697,8 +963,8 @@ public class HashMap<K,V>
return containsNullValue(); return containsNullValue();
Entry<?,?>[] tab = table; Entry<?,?>[] tab = table;
for (int i = 0; i < tab.length ; i++) for (int i = 0; i < tab.length; i++)
for (Entry<?,?> e = tab[i] ; e != null ; e = e.next) for (Entry<?,?> e = tab[i]; e != null; e = e.next)
if (value.equals(e.value)) if (value.equals(e.value))
return true; return true;
return false; return false;
...@@ -709,8 +975,8 @@ public class HashMap<K,V> ...@@ -709,8 +975,8 @@ public class HashMap<K,V>
*/ */
private boolean containsNullValue() { private boolean containsNullValue() {
Entry<?,?>[] tab = table; Entry<?,?>[] tab = table;
for (int i = 0; i < tab.length ; i++) for (int i = 0; i < tab.length; i++)
for (Entry<?,?> e = tab[i] ; e != null ; e = e.next) for (Entry<?,?> e = tab[i]; e != null; e = e.next)
if (e.value == null) if (e.value == null)
return true; return true;
return false; return false;
......
src/share/classes/java/util/Hashtable.java
浏览文件 @ ad59a26e
/* /*
* Copyright (c) 1994, 2012, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 1994, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
* *
* This code is free software; you can redistribute it and/or modify it * This code is free software; you can redistribute it and/or modify it
...@@ -24,7 +24,11 @@ ...@@ -24,7 +24,11 @@
*/ */
package java.util; package java.util;
import java.io.*; import java.io.*;
import java.util.function.BiConsumer;
import java.util.function.Function;
import java.util.function.BiFunction;
/** /**
* This class implements a hash table, which maps keys to values. Any * This class implements a hash table, which maps keys to values. Any
...@@ -455,6 +459,26 @@ public class Hashtable<K,V> ...@@ -455,6 +459,26 @@ public class Hashtable<K,V>
} }
} }
private void addEntry(int hash, K key, V value, int index) {
modCount++;
Entry<?,?> tab[] = table;
if (count >= threshold) {
// Rehash the table if the threshold is exceeded
rehash();
tab = table;
hash = hash(key);
index = (hash & 0x7FFFFFFF) % tab.length;
}
// Creates the new entry.
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>) tab[index];
tab[index] = new Entry<>(hash, key, value, e);
count++;
}
/** /**
* Maps the specified <code>key</code> to the specified * Maps the specified <code>key</code> to the specified
* <code>value</code> in this hashtable. Neither the key nor the * <code>value</code> in this hashtable. Neither the key nor the
...@@ -492,21 +516,7 @@ public class Hashtable<K,V> ...@@ -492,21 +516,7 @@ public class Hashtable<K,V>
} }
} }
modCount++; addEntry(hash, key, value, index);
if (count >= threshold) {
// Rehash the table if the threshold is exceeded
rehash();
tab = table;
hash = hash(key);
index = (hash & 0x7FFFFFFF) % tab.length;
}
// Creates the new entry.
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
tab[index] = new Entry<>(hash, key, value, e);
count++;
return null; return null;
} }
...@@ -892,6 +902,239 @@ public class Hashtable<K,V> ...@@ -892,6 +902,239 @@ public class Hashtable<K,V>
return h; return h;
} }
@Override
public synchronized V getOrDefault(Object key, V defaultValue) {
V result = get(key);
return (null == result) ? defaultValue : result;
}
@Override
public synchronized void forEach(BiConsumer<? super K, ? super V> action) {
Objects.requireNonNull(action); // explicit check required in case
// table is empty.
Entry<?,?>[] tab = table;
for (Entry<?,?> entry : tab) {
while (entry != null) {
action.accept((K)entry.key, (V)entry.value);
entry = entry.next;
}
}
}
@Override
public synchronized void replaceAll(
BiFunction<? super K, ? super V, ? extends V> function) {
Map.super.replaceAll(function);
}
@Override
public synchronized V putIfAbsent(K key, V value) {
Objects.requireNonNull(value);
// Makes sure the key is not already in the hashtable.
Entry<?,?> tab[] = table;
int hash = hash(key);
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> entry = (Entry<K,V>)tab[index];
for (; entry != null; entry = entry.next) {
if ((entry.hash == hash) && entry.key.equals(key)) {
V old = entry.value;
if (old == null) {
entry.value = value;
}
return old;
}
}
addEntry(hash, key, value, index);
return null;
}
@Override
public synchronized boolean remove(Object key, Object value) {
Objects.requireNonNull(value);
Entry<?,?> tab[] = table;
int hash = hash(key);
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
for (Entry<K,V> prev = null; e != null; prev = e, e = e.next) {
if ((e.hash == hash) && e.key.equals(key) && e.value.equals(value)) {
modCount++;
if (prev != null) {
prev.next = e.next;
} else {
tab[index] = e.next;
}
count--;
e.value = null;
return true;
}
}
return false;
}
@Override
public synchronized boolean replace(K key, V oldValue, V newValue) {
Entry<?,?> tab[] = table;
int hash = hash(key);
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
for (; e != null; e = e.next) {
if ((e.hash == hash) && e.key.equals(key)) {
if (e.value.equals(oldValue)) {
e.value = newValue;
return true;
} else {
return false;
}
}
}
return false;
}
@Override
public synchronized V replace(K key, V value) {
Entry<?,?> tab[] = table;
int hash = hash(key);
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
for (; e != null; e = e.next) {
if ((e.hash == hash) && e.key.equals(key)) {
V oldValue = e.value;
e.value = value;
return oldValue;
}
}
return null;
}
@Override
public synchronized V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
Objects.requireNonNull(mappingFunction);
Entry<?,?> tab[] = table;
int hash = hash(key);
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
for (; e != null; e = e.next) {
if (e.hash == hash && e.key.equals(key)) {
// Hashtable not accept null value
return e.value;
}
}
V newValue = mappingFunction.apply(key);
if (newValue != null) {
addEntry(hash, key, newValue, index);
}
return newValue;
}
@Override
public V computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
Objects.requireNonNull(remappingFunction);
Entry<?,?> tab[] = table;
int hash = hash(key);
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
for (Entry<K,V> prev = null; e != null; prev = e, e = e.next) {
if (e.hash == hash && e.key.equals(key)) {
V newValue = remappingFunction.apply(key, e.value);
if (newValue == null) {
modCount++;
if (prev != null) {
prev.next = e.next;
} else {
tab[index] = e.next;
}
count--;
} else {
e.value = newValue;
}
return newValue;
}
}
return null;
}
@Override
public V compute(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
Objects.requireNonNull(remappingFunction);
Entry<?,?> tab[] = table;
int hash = hash(key);
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
for (Entry<K,V> prev = null; e != null; prev = e, e = e.next) {
if (e.hash == hash && Objects.equals(e.key, key)) {
V newValue = remappingFunction.apply(key, e.value);
if (newValue == null) {
modCount++;
if (prev != null) {
prev.next = e.next;
} else {
tab[index] = e.next;
}
count--;
} else {
e.value = newValue;
}
return newValue;
}
}
V newValue = remappingFunction.apply(key, null);
if (newValue != null) {
addEntry(hash, key, newValue, index);
}
return newValue;
}
@Override
public V merge(K key, V value, BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
Objects.requireNonNull(remappingFunction);
Entry<?,?> tab[] = table;
int hash = hash(key);
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
for (Entry<K,V> prev = null; e != null; prev = e, e = e.next) {
if (e.hash == hash && e.key.equals(key)) {
V newValue = remappingFunction.apply(e.value, value);
if (newValue == null) {
modCount++;
if (prev != null) {
prev.next = e.next;
} else {
tab[index] = e.next;
}
count--;
} else {
e.value = newValue;
}
return newValue;
}
}
if (value != null) {
addEntry(hash, key, value, index);
}
return value;
}
/** /**
* Save the state of the Hashtable to a stream (i.e., serialize it). * Save the state of the Hashtable to a stream (i.e., serialize it).
* *
......
src/share/classes/java/util/Map.java
浏览文件 @ ad59a26e
/* /*
* Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
* *
* This code is free software; you can redistribute it and/or modify it * This code is free software; you can redistribute it and/or modify it
...@@ -25,6 +25,10 @@ ...@@ -25,6 +25,10 @@
package java.util; package java.util;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import java.util.function.Function;
/** /**
* An object that maps keys to values. A map cannot contain duplicate keys; * An object that maps keys to values. A map cannot contain duplicate keys;
* each key can map to at most one value. * each key can map to at most one value.
...@@ -475,4 +479,613 @@ public interface Map<K,V> { ...@@ -475,4 +479,613 @@ public interface Map<K,V> {
*/ */
int hashCode(); int hashCode();
// Defaultable methods
/**
* Returns the value to which the specified key is mapped,
* or {@code defaultValue} if this map contains no mapping
* for the key.
*
* <p>The default implementation makes no guarantees about synchronization
* or atomicity properties of this method. Any implementation providing
* atomicity guarantees must override this method and document its
* concurrency properties.
*
* @param key the key whose associated value is to be returned
* @return the value to which the specified key is mapped, or
* {@code defaultValue} if this map contains no mapping for the key
* @throws ClassCastException if the key is of an inappropriate type for
* this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws NullPointerException if the specified key is null and this map
* does not permit null keys
* (<a href="Collection.html#optional-restrictions">optional</a>)
*/
default V getOrDefault(Object key, V defaultValue) {
V v;
return (((v = get(key)) != null) || containsKey(key))
? v
: defaultValue;
}
/**
* Performs the given action on each entry in this map, in the order entries
* are returned by an entry set iterator (which may be unspecified), until
* all entries have been processed or the action throws an {@code Exception}.
* Exceptions thrown by the action are relayed to the caller.
*
* <p>The default implementation should be overridden by implementations if
* they can provide a more performant implementation than an iterator-based
* one.
*
* <p>The default implementation makes no guarantees about synchronization
* or atomicity properties of this method. Any implementation providing
* atomicity guarantees must override this method and document its
* concurrency properties.
*
* @implSpec The default implementation is equivalent to, for this
* {@code map}:
* <pre> {@code
* for ((Map.Entry<K, V> entry : map.entrySet())
* action.accept(entry.getKey(), entry.getValue());
* }</pre>
*
* @param action The action to be performed for each entry
* @throws NullPointerException if the specified action is null
* @throws ConcurrentModificationException if an entry is found to be
* removed during iteration
* @since 1.8
*/
default void forEach(BiConsumer<? super K, ? super V> action) {
Objects.requireNonNull(action);
for (Map.Entry<K, V> entry : entrySet()) {
K k;
V v;
try {
k = entry.getKey();
v = entry.getValue();
} catch(IllegalStateException ise) {
throw new ConcurrentModificationException(ise);
}
action.accept(k, v);
}
}
/**
* Replaces each entry's value with the result of invoking the given
* function on that entry, in the order entries are returned by an entry
* set iterator, until all entries have been processed or the function
* throws an exception.
*
* <p>The default implementation makes no guarantees about synchronization
* or atomicity properties of this method. Any implementation providing
* atomicity guarantees must override this method and document its
* concurrency properties.
*
* @implSpec
* <p>The default implementation is equivalent to, for this {@code map}:
* <pre> {@code
* for ((Map.Entry<K, V> entry : map.entrySet())
* entry.setValue(function.apply(entry.getKey(), entry.getValue()));
* }</pre>
*
* @param function the function to apply to each entry
* @throws UnsupportedOperationException if the {@code set} operation
* is not supported by this map's entry set iterator.
* @throws ClassCastException if the class of a replacement value
* prevents it from being stored in this map
* @throws NullPointerException if the specified function is null, or the
* specified replacement value is null, and this map does not permit null
* values
* @throws ClassCastException if a replacement value is of an inappropriate
* type for this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws NullPointerException if function or a replacement value is null,
* and this map does not permit null keys or values
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws IllegalArgumentException if some property of a replacement value
* prevents it from being stored in this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws ConcurrentModificationException if an entry is found to be
* removed during iteration
* @since 1.8
*/
default void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
Objects.requireNonNull(function);
for (Map.Entry<K, V> entry : entrySet()) {
K k;
V v;
try {
k = entry.getKey();
v = entry.getValue();
} catch(IllegalStateException ise) {
throw new ConcurrentModificationException(ise);
}
entry.setValue(function.apply(k, v));
}
}
/**
* If the specified key is not already associated with a value (or is mapped
* to {@code null}) associates it with the given value and returns
* {@code null}, else returns the current value.
*
* <p>The default implementation makes no guarantees about synchronization
* or atomicity properties of this method. Any implementation providing
* atomicity guarantees must override this method and document its
* concurrency properties.
*
* @implSpec
* The default implementation is equivalent to, for this {@code
* map}:
*
* <pre> {@code
* if (map.get(key) == null)
* return map.put(key, value);
* else
* return map.get(key);
* }</pre>
*
* @param key key with which the specified value is to be associated
* @param value value to be associated with the specified key
* @return the previous value associated with the specified key, or
* {@code 1} if there was no mapping for the key.
* (A {@code null} return can also indicate that the map
* previously associated {@code null} with the key,
* if the implementation supports null values.)
* @throws UnsupportedOperationException if the {@code put} operation
* is not supported by this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws ClassCastException if the key or value is of an inappropriate
* type for this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws NullPointerException if the specified key or value is null,
* and this map does not permit null keys or values
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws IllegalArgumentException if some property of the specified key
* or value prevents it from being stored in this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws ConcurrentModificationException if a modification of the map is
* detected during insertion of the value.
* @since 1.8
*/
default V putIfAbsent(K key, V value) {
V v = get(key);
if (v == null) {
if (put(key, value) != null) {
throw new ConcurrentModificationException();
}
}
return v;
}
/**
* Removes the entry for the specified key only if it is currently
* mapped to the specified value.
*
* <p>The default implementation makes no guarantees about synchronization
* or atomicity properties of this method. Any implementation providing
* atomicity guarantees must override this method and document its
* concurrency properties.
*
* @implSpec
* The default implementation is equivalent to, for this {@code map}:
*
* <pre> {@code
* if (map.containsKey(key) && Objects.equals(map.get(key), value)) {
* map.remove(key);
* return true;
* } else
* return false;
* }</pre>
*
* @param key key with which the specified value is associated
* @param value value expected to be associated with the specified key
* @return {@code true} if the value was removed
* @throws UnsupportedOperationException if the {@code remove} operation
* is not supported by this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws ClassCastException if the key or value is of an inappropriate
* type for this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws NullPointerException if the specified key or value is null,
* and this map does not permit null keys or values
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @since 1.8
*/
default boolean remove(Object key, Object value) {
Object curValue = get(key);
if (!Objects.equals(curValue, value) ||
(curValue == null && !containsKey(key))) {
return false;
}
remove(key);
return true;
}
/**
* Replaces the entry for the specified key only if currently
* mapped to the specified value.
*
* <p>The default implementation makes no guarantees about synchronization
* or atomicity properties of this method. Any implementation providing
* atomicity guarantees must override this method and document its
* concurrency properties.
*
* @implSpec
* The default implementation is equivalent to, for this {@code map}:
*
* <pre> {@code
* if (map.containsKey(key) && Objects.equals(map.get(key), value)) {
* map.put(key, newValue);
* return true;
* } else
* return false;
* }</pre>
*
* @param key key with which the specified value is associated
* @param oldValue value expected to be associated with the specified key
* @param newValue value to be associated with the specified key
* @return {@code true} if the value was replaced
* @throws UnsupportedOperationException if the {@code put} operation
* is not supported by this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws ClassCastException if the class of a specified key or value
* prevents it from being stored in this map
* @throws NullPointerException if a specified key or value is null,
* and this map does not permit null keys or values
* @throws IllegalArgumentException if some property of a specified key
* or value prevents it from being stored in this map
* @since 1.8
*/
default boolean replace(K key, V oldValue, V newValue) {
Object curValue = get(key);
if (!Objects.equals(curValue, oldValue) ||
(curValue == null && !containsKey(key))) {
return false;
}
put(key, newValue);
return true;
}
/**
* Replaces the entry for the specified key only if it is
* currently mapped to some value.
*
* <p>The default implementation makes no guarantees about synchronization
* or atomicity properties of this method. Any implementation providing
* atomicity guarantees must override this method and document its
* concurrency properties.
*
* @implSpec
* The default implementation is equivalent to, for this {@code map}:
*
* <pre> {@code
* if (map.containsKey(key)) {
* return map.put(key, value);
* } else
* return null;
* }</pre>
*
* @param key key with which the specified value is associated
* @param value value to be associated with the specified key
* @return the previous value associated with the specified key, or
* {@code null} if there was no mapping for the key.
* (A {@code null} return can also indicate that the map
* previously associated {@code null} with the key,
* if the implementation supports null values.)
* @throws UnsupportedOperationException if the {@code put} operation
* is not supported by this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws ClassCastException if the class of the specified key or value
* prevents it from being stored in this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws NullPointerException if the specified key or value is null,
* and this map does not permit null keys or values
* @throws IllegalArgumentException if some property of the specified key
* or value prevents it from being stored in this map
* @since 1.8
*/
default V replace(K key, V value) {
return containsKey(key) ? put(key, value) : null;
}
/**
* If the specified key is not already associated with a value (or
* is mapped to {@code null}), attempts to compute its value using
* the given mapping function and enters it into this map unless
* {@code null}.
*
* <p>If the function returns {@code null} no mapping is recorded. If
* the function itself throws an (unchecked) exception, the
* exception is rethrown, and no mapping is recorded. The most
* common usage is to construct a new object serving as an initial
* mapped value or memoized result, as in:
*
* <pre> {@code
* map.computeIfAbsent(key, k -> new Value(f(k)));
* }</pre>
*
* <p>The default implementation makes no guarantees about synchronization
* or atomicity properties of this method. Any implementation providing
* atomicity guarantees must override this method and document its
* concurrency properties. In particular, all implementations of
* subinterface {@link java.util.concurrent.ConcurrentMap} must document
* whether the function is applied once atomically only if the value is not
* present. Any class that permits null values must document
* whether and how this method distinguishes absence from null mappings.
*
* @implSpec
* The default implementation is equivalent to the following
* steps for this {@code map}, then returning the current value or
* {@code null} if now absent:
*
* <pre> {@code
* if (map.get(key) == null) {
* V newValue = mappingFunction.apply(key);
* if (newValue != null)
* map.putIfAbsent(key, newValue);
* }
* }</pre>
*
* @param key key with which the specified value is to be associated
* @param mappingFunction the function to compute a value
* @return the current (existing or computed) value associated with
* the specified key, or null if the computed value is null
* @throws NullPointerException if the specified key is null and
* this map does not support null keys, or the
* mappingFunction is null
* @throws UnsupportedOperationException if the {@code put} operation
* is not supported by this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws ClassCastException if the class of the specified key or value
* prevents it from being stored in this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @since 1.8
*/
default V computeIfAbsent(K key,
Function<? super K, ? extends V> mappingFunction) {
V v, newValue;
return ((v = get(key)) == null &&
(newValue = mappingFunction.apply(key)) != null &&
(v = putIfAbsent(key, newValue)) == null) ? newValue : v;
}
/**
* If the value for the specified key is present and non-null, attempts to
* compute a new mapping given the key and its current mapped value.
*
* <p>If the function returns {@code null}, the mapping is removed. If the
* function itself throws an (unchecked) exception, the exception is
* rethrown, and the current mapping is left unchanged.
*
* <p>The default implementation makes no guarantees about synchronization
* or atomicity properties of this method. Any implementation providing
* atomicity guarantees must override this method and document its
* concurrency properties. In particular, all implementations of
* subinterface {@link java.util.concurrent.ConcurrentMap} must document
* whether the function is applied once atomically only if the value is not
* present. Any class that permits null values must document
* whether and how this method distinguishes absence from null mappings.
*
* @implSpec
* The default implementation is equivalent to performing the
* following steps for this {@code map}, then returning the
* current value or {@code null} if now absent:
*
* <pre> {@code
* if (map.get(key) != null) {
* V oldValue = map.get(key);
* V newValue = remappingFunction.apply(key, oldValue);
* if (newValue != null)
* map.replace(key, oldValue, newValue);
* else
* map.remove(key, oldValue);
* }
* }</pre>
*
* In concurrent contexts, the default implementation may retry
* these steps when multiple threads attempt updates.
*
* @param key key with which the specified value is to be associated
* @param remappingFunction the function to compute a value
* @return the new value associated with the specified key, or null if none
* @throws NullPointerException if the specified key is null and
* this map does not support null keys, or the
* remappingFunction is null
* @throws UnsupportedOperationException if the {@code put} operation
* is not supported by this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws ClassCastException if the class of the specified key or value
* prevents it from being stored in this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @since 1.8
*/
default V computeIfPresent(K key,
BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
V oldValue;
while ((oldValue = get(key)) != null) {
V newValue = remappingFunction.apply(key, oldValue);
if (newValue != null) {
if (replace(key, oldValue, newValue))
return newValue;
} else if (remove(key, oldValue))
return null;
}
return oldValue;
}
/**
* Attempts to compute a mapping for the specified key and its
* current mapped value (or {@code null} if there is no current
* mapping). For example, to either create or append a {@code
* String msg} to a value mapping:
*
* <pre> {@code
* map.compute(key, (k, v) -> (v == null) ? msg : v.concat(msg))}</pre>
* (Method {@link #merge merge()} is often simpler to use for such purposes.)
*
* <p>If the function returns {@code null}, the mapping is removed (or
* remains absent if initially absent). If the function itself throws an
* (unchecked) exception, the exception is rethrown, and the current mapping
* is left unchanged.
*
* <p>The default implementation makes no guarantees about synchronization
* or atomicity properties of this method. Any implementation providing
* atomicity guarantees must override this method and document its
* concurrency properties. In particular, all implementations of
* subinterface {@link java.util.concurrent.ConcurrentMap} must document
* whether the function is applied once atomically only if the value is not
* present. Any class that permits null values must document
* whether and how this method distinguishes absence from null mappings.
*
* @implSpec
* The default implementation is equivalent to performing the following
* steps for this {@code map}, then returning the current value or
* {@code null} if absent:
*
* <pre> {@code
* V oldValue = map.get(key);
* V newValue = remappingFunction.apply(key, oldValue);
* if (oldValue != null ) {
* if (newValue != null)
* map.replace(key, oldValue, newValue);
* else
* map.remove(key, oldValue);
* } else {
* if (newValue != null)
* map.putIfAbsent(key, newValue);
* else
* return null;
* }
* }</pre>
*
* In concurrent contexts, the default implementation may retry
* these steps when multiple threads attempt updates.
*
* @param key key with which the specified value is to be associated
* @param remappingFunction the function to compute a value
* @return the new value associated with the specified key, or null if none
* @throws NullPointerException if the specified key is null and
* this map does not support null keys, or the
* remappingFunction is null
* @throws UnsupportedOperationException if the {@code put} operation
* is not supported by this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws ClassCastException if the class of the specified key or value
* prevents it from being stored in this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @since 1.8
*/
default V compute(K key,
BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
V oldValue = get(key);
for (;;) {
V newValue = remappingFunction.apply(key, oldValue);
if (oldValue != null) {
if (newValue != null) {
if (replace(key, oldValue, newValue))
return newValue;
} else if (remove(key, oldValue)) {
return null;
}
oldValue = get(key);
} else {
if (newValue != null) {
if ((oldValue = putIfAbsent(key, newValue)) == null)
return newValue;
} else {
return null;
}
}
}
}
/**
* If the specified key is not already associated with a value or is
* associated with null, associates it with the given value.
* Otherwise, replaces the value with the results of the given
* remapping function, or removes if the result is {@code null}. This
* method may be of use when combining multiple mapped values for a key.
* For example, to either create or append a {@code String msg} to a
* value mapping:
*
* <pre> {@code
* map.merge(key, msg, String::concat)
* }</pre>
*
* <p>If the function returns {@code null}, the mapping is removed (or
* remains absent if initially absent). If the function itself throws an
* (unchecked) exception, the exception is rethrown, and the current mapping
* is left unchanged.
*
* <p>The default implementation makes no guarantees about synchronization
* or atomicity properties of this method. Any implementation providing
* atomicity guarantees must override this method and document its
* concurrency properties. In particular, all implementations of
* subinterface {@link java.util.concurrent.ConcurrentMap} must document
* whether the function is applied once atomically only if the value is not
* present. Any class that permits null values must document
* whether and how this method distinguishes absence from null mappings.
*
* @implSpec
* The default implementation is equivalent to performing the
* following steps for this {@code map}, then returning the
* current value or {@code null} if absent:
*
* <pre> {@code
* V oldValue = map.get(key);
* V newValue = (oldValue == null) ? value :
* remappingFunction.apply(oldValue, value);
* if (newValue == null)
* map.remove(key, oldValue);
* else if (oldValue == null)
* map.putIfAbsent(key, newValue);
* else
* map.replace(key, oldValue, newValue);
* }</pre>
*
* In concurrent contexts, the default implementation may retry
* these steps when multiple threads attempt updates.
*
* @param key key with which the specified value is to be associated
* @param value the value to use if absent
* @param remappingFunction the function to recompute a value if present
* @return the new value associated with the specified key, or null if none
* @throws UnsupportedOperationException if the {@code put} operation
* is not supported by this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws ClassCastException if the class of the specified key or value
* prevents it from being stored in this map
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws NullPointerException if the specified key is null and
* this map does not support null keys, or the
* remappingFunction is null
* @since 1.8
*/
default V merge(K key, V value,
BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
V oldValue = get(key);
for (;;) {
if (oldValue != null) {
V newValue = remappingFunction.apply(oldValue, value);
if (newValue != null) {
if (replace(key, oldValue, newValue))
return newValue;
} else if (remove(key, oldValue)) {
return null;
}
oldValue = get(key);
} else {
if (value == null) {
return null;
}
if ((oldValue = putIfAbsent(key, value)) == null) {
return value;
}
}
}
}
} }
src/share/classes/java/util/concurrent/ConcurrentMap.java
浏览文件 @ ad59a26e
...@@ -38,7 +38,7 @@ import java.util.Map; ...@@ -38,7 +38,7 @@ import java.util.Map;
/** /**
* A {@link java.util.Map} providing additional atomic * A {@link java.util.Map} providing additional atomic
* <tt>putIfAbsent</tt>, <tt>remove</tt>, and <tt>replace</tt> methods. * {@code putIfAbsent}, {@code remove}, and {@code replace} methods.
* *
* <p>Memory consistency effects: As with other concurrent * <p>Memory consistency effects: As with other concurrent
* collections, actions in a thread prior to placing an object into a * collections, actions in a thread prior to placing an object into a
...@@ -57,6 +57,21 @@ import java.util.Map; ...@@ -57,6 +57,21 @@ import java.util.Map;
* @param <V> the type of mapped values * @param <V> the type of mapped values
*/ */
public interface ConcurrentMap<K, V> extends Map<K, V> { public interface ConcurrentMap<K, V> extends Map<K, V> {
/**
* {@inheritDoc}
*
* @implNote This implementation assumes that the ConcurrentMap cannot
* contain null values and get() returning null unambiguously means the key
* is absent. Implementations which support null values must override this
* default implementation.
*/
@Override
default V getOrDefault(Object key, V defaultValue) {
V v;
return ((v = get(key)) != null) ? v : defaultValue;
}
/** /**
* If the specified key is not already associated * If the specified key is not already associated
* with a value, associate it with the given value. * with a value, associate it with the given value.
...@@ -91,7 +106,7 @@ public interface ConcurrentMap<K, V> extends Map<K, V> { ...@@ -91,7 +106,7 @@ public interface ConcurrentMap<K, V> extends Map<K, V> {
* Removes the entry for a key only if currently mapped to a given value. * Removes the entry for a key only if currently mapped to a given value.
* This is equivalent to * This is equivalent to
* <pre> {@code * <pre> {@code
* if (map.containsKey(key) && map.get(key).equals(value)) { * if (map.containsKey(key) && Objects.equals(map.get(key), value)) {
* map.remove(key); * map.remove(key);
* return true; * return true;
* } else * } else
...@@ -101,8 +116,8 @@ public interface ConcurrentMap<K, V> extends Map<K, V> { ...@@ -101,8 +116,8 @@ public interface ConcurrentMap<K, V> extends Map<K, V> {
* *
* @param key key with which the specified value is associated * @param key key with which the specified value is associated
* @param value value expected to be associated with the specified key * @param value value expected to be associated with the specified key
* @return <tt>true</tt> if the value was removed * @return {@code true} if the value was removed
* @throws UnsupportedOperationException if the <tt>remove</tt> operation * @throws UnsupportedOperationException if the {@code remove} operation
* is not supported by this map * is not supported by this map
* @throws ClassCastException if the key or value is of an inappropriate * @throws ClassCastException if the key or value is of an inappropriate
* type for this map * type for this map
...@@ -117,7 +132,7 @@ public interface ConcurrentMap<K, V> extends Map<K, V> { ...@@ -117,7 +132,7 @@ public interface ConcurrentMap<K, V> extends Map<K, V> {
* Replaces the entry for a key only if currently mapped to a given value. * Replaces the entry for a key only if currently mapped to a given value.
* This is equivalent to * This is equivalent to
* <pre> {@code * <pre> {@code
* if (map.containsKey(key) && map.get(key).equals(oldValue)) { * if (map.containsKey(key) && Objects.equals(map.get(key), oldValue)) {
* map.put(key, newValue); * map.put(key, newValue);
* return true; * return true;
* } else * } else
...@@ -128,8 +143,8 @@ public interface ConcurrentMap<K, V> extends Map<K, V> { ...@@ -128,8 +143,8 @@ public interface ConcurrentMap<K, V> extends Map<K, V> {
* @param key key with which the specified value is associated * @param key key with which the specified value is associated
* @param oldValue value expected to be associated with the specified key * @param oldValue value expected to be associated with the specified key
* @param newValue value to be associated with the specified key * @param newValue value to be associated with the specified key
* @return <tt>true</tt> if the value was replaced * @return {@code true} if the value was replaced
* @throws UnsupportedOperationException if the <tt>put</tt> operation * @throws UnsupportedOperationException if the {@code put} operation
* is not supported by this map * is not supported by this map
* @throws ClassCastException if the class of a specified key or value * @throws ClassCastException if the class of a specified key or value
* prevents it from being stored in this map * prevents it from being stored in this map
...@@ -154,11 +169,11 @@ public interface ConcurrentMap<K, V> extends Map<K, V> { ...@@ -154,11 +169,11 @@ public interface ConcurrentMap<K, V> extends Map<K, V> {
* @param key key with which the specified value is associated * @param key key with which the specified value is associated
* @param value value to be associated with the specified key * @param value value to be associated with the specified key
* @return the previous value associated with the specified key, or * @return the previous value associated with the specified key, or
* <tt>null</tt> if there was no mapping for the key. * {@code null} if there was no mapping for the key.
* (A <tt>null</tt> return can also indicate that the map * (A {@code null} return can also indicate that the map
* previously associated <tt>null</tt> with the key, * previously associated {@code null} with the key,
* if the implementation supports null values.) * if the implementation supports null values.)
* @throws UnsupportedOperationException if the <tt>put</tt> operation * @throws UnsupportedOperationException if the {@code put} operation
* is not supported by this map * is not supported by this map
* @throws ClassCastException if the class of the specified key or value * @throws ClassCastException if the class of the specified key or value
* prevents it from being stored in this map * prevents it from being stored in this map
......
test/java/util/Map/Defaults.java 0 → 100644
浏览文件 @ ad59a26e
/*
* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @bug 8010122 8004518
* @summary Test Map default methods
* @author Mike Duigou
* @run testng Defaults
*/
import java.util.AbstractMap;
import java.util.AbstractSet;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.EnumMap;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.IdentityHashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.TreeMap;
import java.util.Set;
import java.util.WeakHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentSkipListMap;
import java.util.function.Supplier;
import org.testng.annotations.Test;
import org.testng.annotations.DataProvider;
import static org.testng.Assert.fail;
import static org.testng.Assert.assertEquals;
import static org.testng.Assert.assertTrue;
import static org.testng.Assert.assertFalse;
import static org.testng.Assert.assertNull;
import static org.testng.Assert.assertSame;
public class Defaults {
@Test(dataProvider = "Nulls Map<IntegerEnum,String>")
public void testGetOrDefaultNulls(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(null), "null key absent");
assertNull(map.get(null), "value not null");
assertSame(map.get(null), map.getOrDefault(null, EXTRA_VALUE), "values should match");
}
@Test(dataProvider = "Map<IntegerEnum,String>")
public void testGetOrDefault(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(KEYS[1]), "expected key missing");
assertSame(map.get(KEYS[1]), map.getOrDefault(KEYS[1], EXTRA_VALUE), "values should match");
assertFalse(map.containsKey(EXTRA_KEY), "expected absent key");
assertSame(map.getOrDefault(EXTRA_KEY, EXTRA_VALUE), EXTRA_VALUE, "value not returned as default");
assertNull(map.getOrDefault(EXTRA_KEY, null), "null not returned as default");
}
@Test(dataProvider = "R/W Nulls Map<IntegerEnum,String>")
public void testPutIfAbsentNulls(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(null), "null key absent");
assertNull(map.get(null), "value not null");
assertNull(map.putIfAbsent(null, EXTRA_VALUE), "previous not null");
assertTrue(map.containsKey(null), "null key absent");
assertSame(map.get(null), EXTRA_VALUE, "unexpected value");
assertSame(map.putIfAbsent(null, null), EXTRA_VALUE, "previous not expected value");
assertTrue(map.containsKey(null), "null key absent");
assertSame(map.get(null), EXTRA_VALUE, "unexpected value");
assertSame(map.remove(null), EXTRA_VALUE, "removed unexpected value");
assertFalse(map.containsKey(null), description + ": key present after remove");
assertNull(map.putIfAbsent(null, null), "previous not null");
assertTrue(map.containsKey(null), "null key absent");
assertNull(map.get(null), "value not null");
assertNull(map.putIfAbsent(null, EXTRA_VALUE), "previous not null");
assertSame(map.get(null), EXTRA_VALUE, "value not expected");
}
@Test(dataProvider = "R/W Map<IntegerEnum,String>")
public void testPutIfAbsent(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(KEYS[1]));
Object expected = map.get(KEYS[1]);
assertTrue(null == expected || expected == VALUES[1]);
assertSame(map.putIfAbsent(KEYS[1], EXTRA_VALUE), expected);
assertSame(map.get(KEYS[1]), expected);
assertFalse(map.containsKey(EXTRA_KEY));
assertSame(map.putIfAbsent(EXTRA_KEY, EXTRA_VALUE), null);
assertSame(map.get(EXTRA_KEY), EXTRA_VALUE);
}
@Test(dataProvider = "Nulls Map<IntegerEnum,String>")
public void testForEach(String description, Map<IntegerEnum, String> map) {
IntegerEnum[] EACH_KEY = new IntegerEnum[map.size()];
map.forEach((k, v) -> {
int idx = (null == k) ? 0 : k.ordinal(); // substitute for index.
assertNull(EACH_KEY[idx]);
EACH_KEY[idx] = (idx == 0) ? KEYS[0] : k; // substitute for comparison.
assertSame(v, map.get(k));
});
assertEquals(KEYS, EACH_KEY);
}
@Test(dataProvider = "R/W Nulls Map<IntegerEnum,String>")
public static void testRemoveNulls(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(null), "null key absent");
assertNull(map.get(null), "value not null");
assertFalse(map.remove(null, EXTRA_VALUE), description);
assertTrue(map.containsKey(null));
assertNull(map.get(null));
assertTrue(map.remove(null, null));
assertFalse(map.containsKey(null));
assertNull(map.get(null));
assertFalse(map.remove(null, null));
}
@Test(dataProvider = "R/W Map<IntegerEnum,String>")
public static void testRemove(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(KEYS[1]));
Object expected = map.get(KEYS[1]);
assertTrue(null == expected || expected == VALUES[1]);
assertFalse(map.remove(KEYS[1], EXTRA_VALUE), description);
assertSame(map.get(KEYS[1]), expected);
assertTrue(map.remove(KEYS[1], expected));
assertNull(map.get(KEYS[1]));
assertFalse(map.remove(KEYS[1], expected));
assertFalse(map.containsKey(EXTRA_KEY));
assertFalse(map.remove(EXTRA_KEY, EXTRA_VALUE));
}
@Test(dataProvider = "R/W Nulls Map<IntegerEnum,String>")
public void testReplaceKVNulls(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(null), "null key absent");
assertNull(map.get(null), "value not null");
assertSame(map.replace(null, EXTRA_VALUE), null);
assertSame(map.get(null), EXTRA_VALUE);
}
@Test(dataProvider = "R/W Map<IntegerEnum,String>")
public void testReplaceKV(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(KEYS[1]));
Object expected = map.get(KEYS[1]);
assertTrue(null == expected || expected == VALUES[1]);
assertSame(map.replace(KEYS[1], EXTRA_VALUE), expected);
assertSame(map.get(KEYS[1]), EXTRA_VALUE);
assertFalse(map.containsKey(EXTRA_KEY));
assertNull(map.replace(EXTRA_KEY, EXTRA_VALUE));
assertFalse(map.containsKey(EXTRA_KEY));
assertNull(map.get(EXTRA_KEY));
assertNull(map.put(EXTRA_KEY, EXTRA_VALUE));
assertSame(map.get(EXTRA_KEY), EXTRA_VALUE);
assertSame(map.replace(EXTRA_KEY, (String)expected), EXTRA_VALUE);
assertSame(map.get(EXTRA_KEY), expected);
}
@Test(dataProvider = "R/W Nulls Map<IntegerEnum,String>")
public void testReplaceKVVNulls(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(null), "null key absent");
assertNull(map.get(null), "value not null");
assertFalse(map.replace(null, EXTRA_VALUE, EXTRA_VALUE));
assertNull(map.get(null));
assertTrue(map.replace(null, null, EXTRA_VALUE));
assertSame(map.get(null), EXTRA_VALUE);
assertTrue(map.replace(null, EXTRA_VALUE, EXTRA_VALUE));
assertSame(map.get(null), EXTRA_VALUE);
}
@Test(dataProvider = "R/W Map<IntegerEnum,String>")
public void testReplaceKVV(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(KEYS[1]));
Object expected = map.get(KEYS[1]);
assertTrue(null == expected || expected == VALUES[1]);
assertFalse(map.replace(KEYS[1], EXTRA_VALUE, EXTRA_VALUE));
assertSame(map.get(KEYS[1]), expected);
assertTrue(map.replace(KEYS[1], (String)expected, EXTRA_VALUE));
assertSame(map.get(KEYS[1]), EXTRA_VALUE);
assertTrue(map.replace(KEYS[1], EXTRA_VALUE, EXTRA_VALUE));
assertSame(map.get(KEYS[1]), EXTRA_VALUE);
assertFalse(map.containsKey(EXTRA_KEY));
assertFalse(map.replace(EXTRA_KEY, EXTRA_VALUE, EXTRA_VALUE));
assertFalse(map.containsKey(EXTRA_KEY));
assertNull(map.get(EXTRA_KEY));
assertNull(map.put(EXTRA_KEY, EXTRA_VALUE));
assertTrue(map.containsKey(EXTRA_KEY));
assertSame(map.get(EXTRA_KEY), EXTRA_VALUE);
assertTrue(map.replace(EXTRA_KEY, EXTRA_VALUE, EXTRA_VALUE));
assertSame(map.get(EXTRA_KEY), EXTRA_VALUE);
}
@Test(dataProvider = "R/W Nulls Map<IntegerEnum,String>")
public void testComputeIfAbsentNulls(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(null), "null key absent");
assertNull(map.get(null), "value not null");
assertSame(map.computeIfAbsent(null, (k) -> EXTRA_VALUE), EXTRA_VALUE, description);
assertSame(map.get(null), EXTRA_VALUE, description);
}
@Test(dataProvider = "R/W Map<IntegerEnum,String>")
public void testComputeIfAbsent(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(KEYS[1]));
Object expected = map.get(KEYS[1]);
assertTrue(null == expected || expected == VALUES[1], description + String.valueOf(expected));
expected = (null == expected) ? EXTRA_VALUE : expected;
assertSame(map.computeIfAbsent(KEYS[1], (k) -> EXTRA_VALUE), expected, description);
assertSame(map.get(KEYS[1]), expected, description);
assertFalse(map.containsKey(EXTRA_KEY));
assertSame(map.computeIfAbsent(EXTRA_KEY, (k) -> EXTRA_VALUE), EXTRA_VALUE);
assertSame(map.get(EXTRA_KEY), EXTRA_VALUE);
}
@Test(dataProvider = "R/W Nulls Map<IntegerEnum,String>")
public void testComputeIfPresentNulls(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(null));
assertNull(map.get(null));
assertSame(map.computeIfPresent(null, (k, v) -> {
fail();
return EXTRA_VALUE;
}), null, description);
assertTrue(map.containsKey(null));
assertSame(map.get(null), null, description);
}
@Test(dataProvider = "R/W Map<IntegerEnum,String>")
public void testComputeIfPresent(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(KEYS[1]));
Object value = map.get(KEYS[1]);
assertTrue(null == value || value == VALUES[1], description + String.valueOf(value));
Object expected = (null == value) ? null : EXTRA_VALUE;
assertSame(map.computeIfPresent(KEYS[1], (k, v) -> {
assertSame(v, value);
return EXTRA_VALUE;
}), expected, description);
assertSame(map.get(KEYS[1]), expected, description);
assertFalse(map.containsKey(EXTRA_KEY));
assertSame(map.computeIfPresent(EXTRA_KEY, (k, v) -> {
fail();
return EXTRA_VALUE;
}), null);
assertFalse(map.containsKey(EXTRA_KEY));
assertSame(map.get(EXTRA_KEY), null);
}
@Test(dataProvider = "R/W Nulls Map<IntegerEnum,String>")
public void testComputeNulls(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(null), "null key absent");
assertNull(map.get(null), "value not null");
assertSame(map.compute(null, (k, v) -> {
assertSame(k, null);
assertNull(v);
return EXTRA_VALUE;
}), EXTRA_VALUE, description);
assertTrue(map.containsKey(null));
assertSame(map.get(null), EXTRA_VALUE, description);
assertSame(map.remove(null), EXTRA_VALUE, "removed value not expected");
assertFalse(map.containsKey(null), "null key present");
assertSame(map.compute(null, (k, v) -> {
assertSame(k, null);
assertNull(v);
return null;
}), null, description);
}
@Test(dataProvider = "R/W Map<IntegerEnum,String>")
public void testCompute(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(KEYS[1]));
Object value = map.get(KEYS[1]);
assertTrue(null == value || value == VALUES[1], description + String.valueOf(value));
assertSame(map.compute(KEYS[1], (k, v) -> {
assertSame(k, KEYS[1]);
assertSame(v, value);
return EXTRA_VALUE;
}), EXTRA_VALUE, description);
assertSame(map.get(KEYS[1]), EXTRA_VALUE, description);
assertNull(map.compute(KEYS[1], (k, v) -> {
assertSame(v, EXTRA_VALUE);
return null;
}), description);
assertFalse(map.containsKey(KEYS[1]));
assertFalse(map.containsKey(EXTRA_KEY));
assertSame(map.compute(EXTRA_KEY, (k, v) -> {
assertNull(v);
return EXTRA_VALUE;
}), EXTRA_VALUE);
assertTrue(map.containsKey(EXTRA_KEY));
assertSame(map.get(EXTRA_KEY), EXTRA_VALUE);
}
@Test(dataProvider = "R/W Nulls Map<IntegerEnum,String>")
public void testMergeNulls(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(null), "null key absent");
assertNull(map.get(null), "value not null");
assertSame(map.merge(null, EXTRA_VALUE, (v, vv) -> {
assertNull(v);
assertSame(vv, EXTRA_VALUE);
return vv;
}), EXTRA_VALUE, description);
assertTrue(map.containsKey(null));
assertSame(map.get(null), EXTRA_VALUE, description);
}
@Test(dataProvider = "R/W Map<IntegerEnum,String>")
public void testMerge(String description, Map<IntegerEnum, String> map) {
assertTrue(map.containsKey(KEYS[1]));
Object value = map.get(KEYS[1]);
assertTrue(null == value || value == VALUES[1], description + String.valueOf(value));
assertSame(map.merge(KEYS[1], EXTRA_VALUE, (v, vv) -> {
assertSame(v, value);
assertSame(vv, EXTRA_VALUE);
return vv;
}), EXTRA_VALUE, description);
assertSame(map.get(KEYS[1]), EXTRA_VALUE, description);
assertNull(map.merge(KEYS[1], EXTRA_VALUE, (v, vv) -> {
assertSame(v, EXTRA_VALUE);
assertSame(vv, EXTRA_VALUE);
return null;
}), description);
assertFalse(map.containsKey(KEYS[1]));
assertFalse(map.containsKey(EXTRA_KEY));
assertSame(map.merge(EXTRA_KEY, EXTRA_VALUE, (v, vv) -> {
assertNull(v);
assertSame(vv, EXTRA_VALUE);
return EXTRA_VALUE;
}), EXTRA_VALUE);
assertTrue(map.containsKey(EXTRA_KEY));
assertSame(map.get(EXTRA_KEY), EXTRA_VALUE);
}
enum IntegerEnum {
e0, e1, e2, e3, e4, e5, e6, e7, e8, e9,
e10, e11, e12, e13, e14, e15, e16, e17, e18, e19,
e20, e21, e22, e23, e24, e25, e26, e27, e28, e29,
e30, e31, e32, e33, e34, e35, e36, e37, e38, e39,
e40, e41, e42, e43, e44, e45, e46, e47, e48, e49,
e50, e51, e52, e53, e54, e55, e56, e57, e58, e59,
e60, e61, e62, e63, e64, e65, e66, e67, e68, e69,
e70, e71, e72, e73, e74, e75, e76, e77, e78, e79,
e80, e81, e82, e83, e84, e85, e86, e87, e88, e89,
e90, e91, e92, e93, e94, e95, e96, e97, e98, e99,
EXTRA_KEY;
public static final int SIZE = values().length;
};
private static final int TEST_SIZE = IntegerEnum.SIZE - 1;
/**
* Realized keys ensure that there is always a hard ref to all test objects.
*/
private static final IntegerEnum[] KEYS = new IntegerEnum[TEST_SIZE];
/**
* Realized values ensure that there is always a hard ref to all test
* objects.
*/
private static final String[] VALUES = new String[TEST_SIZE];
static {
IntegerEnum[] keys = IntegerEnum.values();
for (int each = 0; each < TEST_SIZE; each++) {
KEYS[each] = keys[each];
VALUES[each] = String.valueOf(each);
}
}
private static final IntegerEnum EXTRA_KEY = IntegerEnum.EXTRA_KEY;
private static final String EXTRA_VALUE = String.valueOf(TEST_SIZE);
@DataProvider(name = "Map<IntegerEnum,String>", parallel = true)
public static Iterator<Object[]> allNullsMapProvider() {
return makeAllMaps().iterator();
}
@DataProvider(name = "Nulls Map<IntegerEnum,String>", parallel = true)
public static Iterator<Object[]> allMapProvider() {
return makeRWMaps(true).iterator();
}
@DataProvider(name = "R/W Map<IntegerEnum,String>", parallel = true)
public static Iterator<Object[]> rwMapProvider() {
return makeRWMapsNoNulls().iterator();
}
@DataProvider(name = "R/W Nulls Map<IntegerEnum,String>", parallel = true)
public static Iterator<Object[]> rwNullsMapProvider() {
return makeRWMaps(true).iterator();
}
private static Collection<Object[]> makeAllMapsNoNulls() {
Collection<Object[]> all = new ArrayList<>();
all.addAll(makeRWMaps(false));
all.addAll(makeRWNoNullsMaps());
all.addAll(makeROMaps(false));
return all;
}
private static Collection<Object[]> makeRWMapsNoNulls() {
Collection<Object[]> all = new ArrayList<>();
all.addAll(makeRWMaps(false));
all.addAll(makeRWNoNullsMaps());
return all;
}
private static Collection<Object[]> makeAllMaps() {
Collection<Object[]> all = new ArrayList<>();
all.addAll(makeROMaps(false));
all.addAll(makeRWMaps(false));
all.addAll(makeRWNoNullsMaps());
all.addAll(makeRWMaps(true));
all.addAll(makeROMaps(true));
return all;
}
private static Collection<Object[]> makeAllRWMaps() {
Collection<Object[]> all = new ArrayList<>();
all.addAll(makeRWMaps(false));
all.addAll(makeRWNoNullsMaps());
all.addAll(makeRWMaps(true));
return all;
}
private static Collection<Object[]> makeRWMaps(boolean nulls) {
return Arrays.asList(
new Object[]{"HashMap", makeMap(HashMap::new, nulls)},
new Object[]{"IdentityHashMap", makeMap(IdentityHashMap::new, nulls)},
new Object[]{"LinkedHashMap", makeMap(LinkedHashMap::new, nulls)},
new Object[]{"WeakHashMap", makeMap(WeakHashMap::new, nulls)},
new Object[]{"Collections.checkedMap(HashMap)", Collections.checkedMap(makeMap(HashMap::new, nulls), IntegerEnum.class, String.class)},
new Object[]{"Collections.synchronizedMap(HashMap)", Collections.synchronizedMap(makeMap(HashMap::new, nulls))},
new Object[]{"ExtendsAbstractMap", makeMap(ExtendsAbstractMap::new, nulls)});
}
private static Collection<Object[]> makeRWNoNullsMaps() {
return Arrays.asList(
// null hostile
new Object[]{"EnumMap", makeMap(() -> new EnumMap(IntegerEnum.class), false)},
new Object[]{"Hashtable", makeMap(Hashtable::new, false)},
new Object[]{"TreeMap", makeMap(TreeMap::new, false)},
new Object[]{"ConcurrentHashMap", makeMap(ConcurrentHashMap::new, false)},
new Object[]{"ConcurrentSkipListMap", makeMap(ConcurrentSkipListMap::new, false)},
new Object[]{"Collections.checkedMap(ConcurrentHashMap)", Collections.checkedMap(makeMap(ConcurrentHashMap::new, false), IntegerEnum.class, String.class)},
new Object[]{"Collections.synchronizedMap(EnumMap)", Collections.synchronizedMap(makeMap(() -> new EnumMap(IntegerEnum.class), false))},
new Object[]{"ImplementsConcurrentMap", makeMap(ImplementsConcurrentMap::new, false)});
}
private static Collection<Object[]> makeROMaps(boolean nulls) {
return Arrays.asList(new Object[][]{
new Object[]{"Collections.unmodifiableMap(HashMap)", Collections.unmodifiableMap(makeMap(HashMap::new, nulls))}
});
}
private static Map<IntegerEnum, String> makeMap(Supplier<Map<IntegerEnum, String>> supplier, boolean nulls) {
Map<IntegerEnum, String> result = supplier.get();
for (int each = 0; each < TEST_SIZE; each++) {
if (nulls) {
result.put((each == 0) ? null : KEYS[each], null);
} else {
result.put(KEYS[each], VALUES[each]);
}
}
return result;
}
public interface Thrower<T extends Throwable> {
public void run() throws T;
}
public static <T extends Throwable> void assertThrows(Thrower<T> thrower, Class<T> throwable) {
assertThrows(thrower, throwable, null);
}
public static <T extends Throwable> void assertThrows(Thrower<T> thrower, Class<T> throwable, String message) {
Throwable result;
try {
thrower.run();
result = null;
} catch (Throwable caught) {
result = caught;
}
assertInstance(result, throwable,
(null != message)
? message
: "Failed to throw " + throwable.getCanonicalName());
}
public static <T> void assertInstance(T actual, Class<? extends T> expected) {
assertInstance(expected.isInstance(actual), null);
}
public static <T> void assertInstance(T actual, Class<? extends T> expected, String message) {
assertTrue(expected.isInstance(actual), message);
}
/**
* A simple mutable map implementation that provides only default
* implementations of all methods. ie. none of the Map interface default
* methods have overridden implementations.
*
* @param <K> Type of keys
* @param <V> Type of values
*/
public static class ExtendsAbstractMap<M extends Map<K,V>, K, V> extends AbstractMap<K, V> {
protected final M map;
public ExtendsAbstractMap() { this( (M) new HashMap<K,V>()); }
protected ExtendsAbstractMap(M map) { this.map = map; }
public Set<Map.Entry<K, V>> entrySet() {
return new AbstractSet<Map.Entry<K, V>>() {
public int size() {
return map.size();
}
public Iterator<Map.Entry<K,V>> iterator() {
final Iterator<Map.Entry<K,V>> source = map.entrySet().iterator();
return new Iterator<Map.Entry<K,V>>() {
public boolean hasNext() { return source.hasNext(); }
public Map.Entry<K,V> next() { return source.next(); }
public void remove() { source.remove(); }
};
}
public boolean add(Map.Entry<K,V> e) {
return map.entrySet().add(e);
}
};
}
public V put(K key, V value) {
return map.put(key, value);
}
}
/**
* A simple mutable concurrent map implementation that provides only default
* implementations of all methods. ie. none of the ConcurrentMap interface
* default methods have overridden implementations.
*
* @param <K> Type of keys
* @param <V> Type of values
*/
public static class ImplementsConcurrentMap<K, V> extends ExtendsAbstractMap<ConcurrentMap<K,V>, K, V> implements ConcurrentMap<K,V> {
public ImplementsConcurrentMap() { super(new ConcurrentHashMap<K,V>()); }
// ConcurrentMap reabstracts these methods
public V replace(K k, V v) { return map.replace(k, v); };
public boolean replace(K k, V v, V vv) { return map.replace(k, v, vv); };
public boolean remove(Object k, Object v) { return map.remove(k, v); }
public V putIfAbsent(K k, V v) { return map.putIfAbsent(k, v); }
}
}
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