// *************************************************************************************************************************** | |
// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file * | |
// * distributed with this work for additional information regarding copyright ownership. The ASF licenses this file * | |
// * to you 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 org.apache.juneau.internal; | |
import static org.apache.juneau.internal.ThrowableUtils.*; | |
import java.util.*; | |
import org.apache.juneau.*; | |
/** | |
* Wrapper around a map where the key names are overridden. | |
* | |
* @param <K> The key class type. | |
* @param <V> The value class type. | |
*/ | |
public final class FilteredMap<K,V> extends AbstractMap<K,V> implements Delegate<Map<K,V>> { | |
final Map<K,V> innerMap; | |
final Set<Map.Entry<K,V>> entries; | |
final ClassMeta<Map<K,V>> classMeta; | |
/** | |
* Constructor. | |
* | |
* @param classMeta The class type of the map being wrapped. | |
* @param innerMap The map being wrapped. Must not be <jk>null</jk>. | |
* @param keys The keys in the new map. Must not be <jk>null</jk>. | |
*/ | |
public FilteredMap(ClassMeta<Map<K,V>> classMeta, Map<K,V> innerMap, K[] keys) { | |
assertFieldNotNull(innerMap, "innerMap"); | |
assertFieldNotNull(keys, "keys"); | |
this.classMeta = classMeta; | |
this.innerMap = innerMap; | |
List<Map.Entry<K,V>> l = new ArrayList<>(keys.length); | |
for (K k : keys) | |
if (innerMap.containsKey(k)) | |
l.add(createEntry(k)); | |
entries = new ListSet<>(l); | |
} | |
private Map.Entry<K,V> createEntry(final K key) { | |
return new Map.Entry<K,V>() { | |
@Override /* Map.Entry */ | |
public K getKey() { | |
return key; | |
} | |
@Override /* Map.Entry */ | |
public V getValue() { | |
return innerMap.get(key); | |
} | |
@Override /* Map.Entry */ | |
public V setValue(V v) { | |
return innerMap.put(key, v); | |
} | |
}; | |
} | |
@Override /* Map */ | |
public Set<Map.Entry<K,V>> entrySet() { | |
return entries; | |
} | |
/** | |
* A set with ordered entries (a List with a Set API). | |
*/ | |
private static final class ListSet<E> extends AbstractSet<E> { | |
private List<E> entries; | |
public ListSet(List<E> entries) { | |
this.entries = entries; | |
} | |
@Override /* Set */ | |
public Iterator<E> iterator() { | |
return entries.iterator(); | |
} | |
@Override /* Set */ | |
public int size() { | |
return entries.size(); | |
} | |
} | |
@Override /* Delegate */ | |
public ClassMeta<Map<K,V>> getClassMeta() { | |
return classMeta; | |
} | |
} |