/*

 * 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;

/**

 * Provides a base decorator that allows additional functionality to be

 * added to a {@link java.util.Map.Entry Map.Entry}.

 *

 * @param <K> the type of keys

 * @param <V> the type of mapped values

 * @since 3.0

 */

public abstract class AbstractMapEntryDecorator<K, V> implements Map.Entry<K, V>, KeyValue<K, V> {

    /** The <code>Map.Entry</code> to decorate */

    private final Map.Entry<K, V> entry;

    /**

     * Constructor that wraps (not copies).

     *

     * @param entry  the <code>Map.Entry</code> to decorate, must not be null

     * @throws NullPointerException if the collection is null

     */

    public AbstractMapEntryDecorator(final Map.Entry<K, V> entry) {

        if (entry == null) {

            throw new NullPointerException("Map Entry must not be null.");

        }

        this.entry = entry;

    }

    /**

     * Gets the map being decorated.

     *

     * @return the decorated map

     */

    protected Map.Entry<K, V> getMapEntry() {

        return entry;

    }

    //-----------------------------------------------------------------------

    @Override

    public K getKey() {

        return entry.getKey();

    }

    @Override

    public V getValue() {

        return entry.getValue();

    }

    @Override

    public V setValue(final V object) {

        return entry.setValue(object);

    }

    @Override

    public boolean equals(final Object object) {

        if (object == this) {

            return true;

        }

        return entry.equals(object);

    }

    @Override

    public int hashCode() {

        return entry.hashCode();

    }

    @Override

    public String toString() {

        return entry.toString();

    }

}