    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 */
    017package org.apache.commons.collections4.keyvalue;
    018
    019import java.util.Map;
    020
    021import org.apache.commons.collections4.KeyValue;
    022import org.apache.commons.collections4.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 3.0
    029 */
    030public final class UnmodifiableMapEntry<K, V> extends AbstractMapEntry<K, V> implements Unmodifiable {
    031
    032    /**
    033     * Constructs a new entry with the specified key and given value.
    034     *
    035     * @param key  the key for the entry, may be null
    036     * @param value  the value for the entry, may be null
    037     */
    038    public UnmodifiableMapEntry(final K key, final V value) {
    039        super(key, value);
    040    }
    041
    042    /**
    043     * Constructs a new entry from the specified <code>KeyValue</code>.
    044     *
    045     * @param pair  the pair to copy, must not be null
    046     * @throws NullPointerException if the entry is null
    047     */
    048    public UnmodifiableMapEntry(final KeyValue<? extends K, ? extends V> pair) {
    049        super(pair.getKey(), pair.getValue());
    050    }
    051
    052    /**
    053     * Constructs a new entry from the specified <code>Map.Entry</code>.
    054     *
    055     * @param entry  the entry to copy, must not be null
    056     * @throws NullPointerException if the entry is null
    057     */
    058    public UnmodifiableMapEntry(final Map.Entry<? extends K, ? extends V> entry) {
    059        super(entry.getKey(), entry.getValue());
    060    }
    061
    062    /**
    063     * Throws UnsupportedOperationException.
    064     *
    065     * @param value  the new value
    066     * @return the previous value
    067     * @throws UnsupportedOperationException always
    068     */
    069    @Override
    070    public V setValue(final V value) {
    071        throw new UnsupportedOperationException("setValue() is not supported");
    072    }
    073
    074}