| /* |
| * 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; |
| |
| /** |
| * Base class for key-value pairs. Each pair's key is immutable, but the value |
| * associated with the key can be modified. |
| * |
| * @param <K> The type of the key in the pair. |
| * @param <V> The type of the value in the pair. |
| */ |
| public interface Pair<K, V> { |
| |
| /** |
| * Returns the key corresponding to the pair. |
| * |
| * @return The key corresponding to the pair. |
| */ |
| K getKey(); |
| |
| /** |
| * Returns the value corresponding to the pair. |
| * |
| * @return The value corresponding to the pair. |
| */ |
| V getValue(); |
| |
| /** |
| * Replaces the value corresponding to the pair with the given value. |
| * (optional). |
| * |
| * @param value The new value to be associated the pair's key. |
| * @return The old value corresponding to the pair. |
| * @throws UnsupportedOperationException if the operation is not supported. |
| */ |
| V setValue(V value); |
| } |