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 */ 024@SuppressWarnings("rawtypes") 025public class DelegateMap<T extends Map> extends ObjectMap implements Delegate<T> { 026 private static final long serialVersionUID = 1L; 027 028 private transient ClassMeta<T> classMeta; 029 030 /** 031 * Constructor. 032 * 033 * @param m The metadata object that created this delegate object. 034 * @param session The current bean session. 035 */ 036 public DelegateMap(T m, BeanSession session) { 037 this.classMeta = session.getClassMetaForObject(m); 038 for (Map.Entry e : (Set<Map.Entry>)m.entrySet()) 039 put(StringUtils.stringify(e.getKey()), e.getValue()); 040 } 041 042 @Override /* Delegate */ 043 public ClassMeta<T> getClassMeta() { 044 return classMeta; 045 } 046 047 /** 048 * Remove all but the specified keys from this map. 049 * 050 * <p> 051 * This does not affect the underlying map. 052 * 053 * @param keys The remaining keys in the map (in the specified order). 054 * @return This object (for method chaining). 055 */ 056 public DelegateMap<T> filterKeys(List<String> keys) { 057 ObjectMap m2 = new ObjectMap(); 058 for (String k : keys) 059 if (containsKey(k)) 060 m2.put(k, get(k)); 061 this.clear(); 062 this.putAll(m2); 063 return this; 064 } 065}