    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 *      https://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;
    020import java.util.Map.Entry;
    021
    022import org.apache.commons.collections4.KeyValue;
    023import org.apache.commons.collections4.Unmodifiable;
    024
    025/**
    026 * A {@link Entry Map.Entry} that throws
    027 * UnsupportedOperationException when {@code setValue} is called.
    028 *
    029 * @param <K> The type of keys
    030 * @param <V> The type of mapped values
    031 * @since 3.0
    032 */
    033public final class UnmodifiableMapEntry<K, V> extends AbstractMapEntry<K, V> 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 K key, final V value) {
    042        super(key, value);
    043    }
    044
    045    /**
    046     * Constructs a new entry from the specified {@code KeyValue}.
    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<? extends K, ? extends V> pair) {
    052        super(pair.getKey(), pair.getValue());
    053    }
    054
    055    /**
    056     * Constructs a new entry from the specified {@code Map.Entry}.
    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<? extends K, ? extends V> 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    @Override
    073    public V setValue(final V value) {
    074        throw new UnsupportedOperationException("setValue() is not supported");
    075    }
    076
    077}