001    /* 
002        Licensed to the Apache Software Foundation (ASF) under one
003        or more contributor license agreements.  See the NOTICE file
004        distributed with this work for additional information
005        regarding copyright ownership.  The ASF licenses this file
006        to you under the Apache License, Version 2.0 (the
007        "License"); you may not use this file except in compliance
008        with the License.  You may obtain a copy of the License at
009    
010           http://www.apache.org/licenses/LICENSE-2.0
011    
012        Unless required by applicable law or agreed to in writing,
013        software distributed under the License is distributed on an
014        "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015        KIND, either express or implied.  See the License for the
016        specific language governing permissions and limitations
017        under the License.  
018     */
019    package org.apache.wiki.htmltowiki;
020    
021    import java.util.LinkedHashMap;
022    
023    /**
024     * A LinkedHashMap that does not put null values into the map.
025     * 
026     * @param <K> {@inheritDoc}
027     * @param <V> {@inheritDoc}
028     * 
029     */
030    public class ForgetNullValuesLinkedHashMap<K,V> extends LinkedHashMap<K,V>
031    {
032        private static final long serialVersionUID = 0L;
033        
034        /**
035         *  {@inheritDoc}
036         */
037        public V put( K key, V value )
038        {
039            if( value != null )
040            {
041                return super.put( key, value );
042            }
043            
044            return null;
045        }
046    }