flink-core/src/main/java/org/apache/flink/types/DefaultPair.java

/*
 * 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.flink.types;

/**
 * A default implementation of {@link Pair} which keeps key and value in memory.
 *
 * @param <K> The type of the key in the pair.
 * @param <V> The type of the value in the pair.
 */
public class DefaultPair<K, V> implements Pair<K, V> {

	/** The key of the pair. */
	private final K key;

	/** The value of the pair. */
	private V value;

	public DefaultPair(K key, V value) {
		this.key = key;
		this.value = value;
	}

	@Override
	public K getKey() {
		return key;
	}

	@Override
	public V getValue() {
		return value;
	}

	@Override
	public V setValue(V newValue) {
		V oldValue = this.value;
		this.value = newValue;
		return oldValue;
	}
}