/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package org.apache.commons.collections4.keyvalue;

import java.util.Map;

import org.apache.commons.collections4.KeyValue;

import org.apache.commons.collections4.Unmodifiable;

/**

 * A {@link java.util.Map.Entry Map.Entry} that throws

 * UnsupportedOperationException when <code>setValue</code> is called.

 *

 * @param <K> the type of keys

 * @param <V> the type of mapped values

 * @since 3.0

 */

public final class UnmodifiableMapEntry<K, V> extends AbstractMapEntry<K, V> implements Unmodifiable {

    /**

     * Constructs a new entry with the specified key and given value.

     *

     * @param key  the key for the entry, may be null

     * @param value  the value for the entry, may be null

     */

    public UnmodifiableMapEntry(final K key, final V value) {

        super(key, value);

    }

    /**

     * Constructs a new entry from the specified <code>KeyValue</code>.

     *

     * @param pair  the pair to copy, must not be null

     * @throws NullPointerException if the entry is null

     */

    public UnmodifiableMapEntry(final KeyValue<? extends K, ? extends V> pair) {

        super(pair.getKey(), pair.getValue());

    }

    /**

     * Constructs a new entry from the specified <code>Map.Entry</code>.

     *

     * @param entry  the entry to copy, must not be null

     * @throws NullPointerException if the entry is null

     */

    public UnmodifiableMapEntry(final Map.Entry<? extends K, ? extends V> entry) {

        super(entry.getKey(), entry.getValue());

    }

    /**

     * Throws UnsupportedOperationException.

     *

     * @param value  the new value

     * @return the previous value

     * @throws UnsupportedOperationException always

     */

    @Override

    public V setValue(final V value) {

        throw new UnsupportedOperationException("setValue() is not supported");

    }

}