102 lines
2.5 KiB
Java
102 lines
2.5 KiB
Java
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/*
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* Copyright (C) 2011 The Guava Authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.google.common.collect;
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import java.util.Iterator;
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import java.util.Map;
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import java.util.Set;
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import com.google.common.annotations.GwtCompatible;
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/**
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* Workaround for
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* <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6312706"> EnumMap
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* bug</a>. If you want to pass an {@code EnumMap}, with the intention of using
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* its {@code entrySet()} method, you should wrap the {@code EnumMap} in this
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* class instead.
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*
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* <p>
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* This class is not thread-safe even if the underlying map is.
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*
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* @author Dimitris Andreou
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*/
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@GwtCompatible
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final class WellBehavedMap<K, V> extends ForwardingMap<K, V> {
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private final Map<K, V> delegate;
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private Set<Entry<K, V>> entrySet;
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private WellBehavedMap(Map<K, V> delegate) {
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this.delegate = delegate;
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}
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/**
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* Wraps the given map into a {@code WellBehavedEntriesMap}, which intercepts
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* its {@code entrySet()} method by taking the {@code Set<K> keySet()} and
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* transforming it to {@code Set<Entry<K, V>>}. All other invocations are
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* delegated as-is.
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*/
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static <K, V> WellBehavedMap<K, V> wrap(Map<K, V> delegate) {
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return new WellBehavedMap<K, V>(delegate);
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}
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@Override
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protected Map<K, V> delegate() {
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return delegate;
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}
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@Override
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public Set<Entry<K, V>> entrySet() {
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Set<Entry<K, V>> es = entrySet;
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if (es != null) {
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return es;
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}
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return entrySet = new EntrySet();
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}
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private final class EntrySet extends Maps.EntrySet<K, V> {
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@Override
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Map<K, V> map() {
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return WellBehavedMap.this;
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}
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@Override
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public Iterator<Entry<K, V>> iterator() {
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return new TransformedIterator<K, Entry<K, V>>(keySet().iterator()) {
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@Override
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Entry<K, V> transform(final K key) {
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return new AbstractMapEntry<K, V>() {
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@Override
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public K getKey() {
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return key;
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}
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@Override
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public V getValue() {
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return get(key);
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}
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@Override
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public V setValue(V value) {
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return put(key, value);
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}
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};
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}
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};
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}
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}
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}
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