001// *************************************************************************************************************************** 002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file * 003// * distributed with this work for additional information regarding copyright ownership. The ASF licenses this file * 004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance * 005// * with the License. You may obtain a copy of the License at * 006// * * 007// * http://www.apache.org/licenses/LICENSE-2.0 * 008// * * 009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an * 010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the * 011// * specific language governing permissions and limitations under the License. * 012// *************************************************************************************************************************** 013package org.apache.juneau.internal; 014 015import java.util.*; 016 017import org.apache.juneau.*; 018 019/** 020 * Represents a wrapped {@link Map} where entries in the map can be removed without affecting the underlying map. 021 * 022 * @param <T> The class type of the wrapped bean. 023 */ 024public class DelegateMap<T> extends ObjectMap implements Delegate<T> { 025 private static final long serialVersionUID = 1L; 026 027 private transient ClassMeta<T> classMeta; 028 029 /** 030 * Constructor. 031 * 032 * @param classMeta The metadata object that created this delegate object. 033 */ 034 public DelegateMap(ClassMeta<T> classMeta) { 035 this.classMeta = classMeta; 036 } 037 038 @Override /* Delegate */ 039 public ClassMeta<T> getClassMeta() { 040 return classMeta; 041 } 042 043 /** 044 * Remove all but the specified keys from this map. 045 * 046 * <p> 047 * This does not affect the underlying map. 048 * 049 * @param keys The remaining keys in the map (in the specified order). 050 */ 051 public void filterKeys(List<String> keys) { 052 ObjectMap m2 = new ObjectMap(); 053 for (String k : keys) 054 m2.put(k, get(k)); 055 this.clear(); 056 this.putAll(m2); 057 } 058}