| /** |
| * 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.hadoop.lib.lang; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.lib.util.Check; |
| |
| import java.util.concurrent.Callable; |
| |
| /** |
| * Adapter class that allows <code>Runnable</code>s and <code>Callable</code>s to |
| * be treated as the other. |
| */ |
| @InterfaceAudience.Private |
| public class RunnableCallable implements Callable<Void>, Runnable { |
| private Runnable runnable; |
| private Callable<?> callable; |
| |
| /** |
| * Constructor that takes a runnable. |
| * |
| * @param runnable runnable. |
| */ |
| public RunnableCallable(Runnable runnable) { |
| this.runnable = Check.notNull(runnable, "runnable"); |
| } |
| |
| /** |
| * Constructor that takes a callable. |
| * |
| * @param callable callable. |
| */ |
| public RunnableCallable(Callable<?> callable) { |
| this.callable = Check.notNull(callable, "callable"); |
| } |
| |
| /** |
| * Invokes the wrapped callable/runnable as a callable. |
| * |
| * @return void |
| * |
| * @throws Exception thrown by the wrapped callable/runnable invocation. |
| */ |
| @Override |
| public Void call() throws Exception { |
| if (runnable != null) { |
| runnable.run(); |
| } else { |
| callable.call(); |
| } |
| return null; |
| } |
| |
| /** |
| * Invokes the wrapped callable/runnable as a runnable. |
| * |
| * @throws RuntimeException thrown by the wrapped callable/runnable invocation. |
| */ |
| @Override |
| public void run() { |
| if (runnable != null) { |
| runnable.run(); |
| } else { |
| try { |
| callable.call(); |
| } catch (Exception ex) { |
| throw new RuntimeException(ex); |
| } |
| } |
| } |
| |
| /** |
| * Returns the class name of the wrapper callable/runnable. |
| * |
| * @return the class name of the wrapper callable/runnable. |
| */ |
| @Override |
| public String toString() { |
| return (runnable != null) ? runnable.getClass().getSimpleName() : callable.getClass().getSimpleName(); |
| } |
| } |