| /* |
| * 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.slider.server.services.workflow; |
| |
| import org.apache.hadoop.service.AbstractService; |
| |
| import java.io.Closeable; |
| import java.io.IOException; |
| |
| /** |
| * Service that closes the closeable supplied during shutdown, if not null. |
| * |
| * As the Service interface itself extends Closeable, this service |
| * can be used to shut down other services if desired. |
| */ |
| public class ClosingService<C extends Closeable> extends AbstractService { |
| |
| private C closeable; |
| |
| |
| /** |
| * Construct an instance of the service |
| * @param name service name |
| * @param closeable closeable to close (may be null) |
| */ |
| public ClosingService(String name, |
| C closeable) { |
| super(name); |
| this.closeable = closeable; |
| } |
| |
| /** |
| * Construct an instance of the service, using the default name |
| * @param closeable closeable to close (may be null) |
| */ |
| public ClosingService(C closeable) { |
| this("ClosingService", closeable); |
| } |
| |
| |
| /** |
| * Get the closeable |
| * @return the closeable |
| */ |
| public synchronized C getCloseable() { |
| return closeable; |
| } |
| |
| /** |
| * Set or update the closeable. |
| * @param closeable |
| */ |
| public synchronized void setCloseable(C closeable) { |
| this.closeable = closeable; |
| } |
| |
| /** |
| * Stop routine will close the closeable -if not null - and set the |
| * reference to null afterwards |
| * This operation does raise any exception on the close, though it does |
| * record it |
| */ |
| @Override |
| protected void serviceStop() { |
| C target = getCloseable(); |
| if (target != null) { |
| try { |
| target.close(); |
| } catch (IOException ioe) { |
| noteFailure(ioe); |
| } |
| setCloseable(null); |
| } |
| } |
| } |