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    import org.apache.commons.collections.Unmodifiable;
023    
024    /**
025     * A {@link java.util.Map.Entry Map.Entry} that throws
026     * UnsupportedOperationException when <code>setValue</code> is called.
027     *
028     * @since Commons Collections 3.0
029     * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $
030     * 
031     * @author Stephen Colebourne
032     */
033    public final class UnmodifiableMapEntry extends AbstractMapEntry implements Unmodifiable {
034    
035        /**
036         * Constructs a new entry with the specified key and given value.
037         *
038         * @param key  the key for the entry, may be null
039         * @param value  the value for the entry, may be null
040         */
041        public UnmodifiableMapEntry(final Object key, final Object value) {
042            super(key, value);
043        }
044    
045        /**
046         * Constructs a new entry from the specified <code>KeyValue</code>.
047         *
048         * @param pair  the pair to copy, must not be null
049         * @throws NullPointerException if the entry is null
050         */
051        public UnmodifiableMapEntry(final KeyValue pair) {
052            super(pair.getKey(), pair.getValue());
053        }
054    
055        /**
056         * Constructs a new entry from the specified <code>Map.Entry</code>.
057         *
058         * @param entry  the entry to copy, must not be null
059         * @throws NullPointerException if the entry is null
060         */
061        public UnmodifiableMapEntry(final Map.Entry entry) {
062            super(entry.getKey(), entry.getValue());
063        }
064    
065        /**
066         * Throws UnsupportedOperationException.
067         * 
068         * @param value  the new value
069         * @return the previous value
070         * @throws UnsupportedOperationException always
071         */
072        public Object setValue(Object value) {
073            throw new UnsupportedOperationException("setValue() is not supported");
074        }
075    
076    }