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