001    /*
002     *  Licensed to the Apache Software Foundation (ASF) under one or more
003     *  contributor license agreements.  See the NOTICE file distributed with
004     *  this work for additional information regarding copyright ownership.
005     *  The ASF licenses this file to You under the Apache License, Version 2.0
006     *  (the "License"); you may not use this file except in compliance with
007     *  the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     *  Unless required by applicable law or agreed to in writing, software
012     *  distributed under the License is distributed on an "AS IS" BASIS,
013     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     *  See the License for the specific language governing permissions and
015     *  limitations under the License.
016     */
017    package org.apache.commons.collections.keyvalue;
018    
019    import java.util.Map;
020    
021    import org.apache.commons.collections.KeyValue;
022    
023    /**
024     * Provides a base decorator that allows additional functionality to be
025     * added to a {@link java.util.Map.Entry Map.Entry}.
026     *
027     * @since Commons Collections 3.0
028     * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $
029     * 
030     * @author Stephen Colebourne
031     */
032    public abstract class AbstractMapEntryDecorator implements Map.Entry, KeyValue {
033        
034        /** The <code>Map.Entry</code> to decorate */
035        protected final Map.Entry entry;
036    
037        /**
038         * Constructor that wraps (not copies).
039         *
040         * @param entry  the <code>Map.Entry</code> to decorate, must not be null
041         * @throws IllegalArgumentException if the collection is null
042         */
043        public AbstractMapEntryDecorator(Map.Entry entry) {
044            if (entry == null) {
045                throw new IllegalArgumentException("Map Entry must not be null");
046            }
047            this.entry = entry;
048        }
049    
050        /**
051         * Gets the map being decorated.
052         * 
053         * @return the decorated map
054         */
055        protected Map.Entry getMapEntry() {
056            return entry;
057        }
058    
059        //-----------------------------------------------------------------------
060        public Object getKey() {
061            return entry.getKey();
062        }
063    
064        public Object getValue() {
065            return entry.getValue();
066        }
067    
068        public Object setValue(Object object) {
069            return entry.setValue(object);
070        }
071       
072        public boolean equals(Object object) {
073            if (object == this) {
074                return true;
075            }
076            return entry.equals(object);
077        }
078    
079        public int hashCode() {
080            return entry.hashCode();
081        }
082    
083        public String toString() {
084            return entry.toString();
085        }
086    
087    }