Java tutorial
/* * 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.core.main; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.service.Service; /** * An interface which services can implement to have their * execution managed by the ServiceLauncher. * The command line options will be passed down before the * {@link Service#init(Configuration)} operation is invoked via an * invocation of {@link RunService#bindArgs(Configuration, String...)} * After the service has been successfully started via {@link Service#start()} * the {@link RunService#runService()} method is called to execute the * service. When this method returns, the service launcher will exit, using * the return code from the method as its exit option. */ public interface RunService extends Service { /** * Propagate the command line arguments. * This method is called before {@link Service#init(Configuration)}; * the configuration that is returned from this operation * is the one that is passed on to the init operation. * This permits implemenations to change the configuration before * the init operation.n * * * @param config the initial configuration build up by the * service launcher. * @param args argument list list of arguments passed to the command line * after any launcher-specific commands have been stripped. * @return the configuration to init the service with. This MUST NOT be null. * Recommended: pass down the config parameter with any changes * @throws Exception any problem */ Configuration bindArgs(Configuration config, String... args) throws Exception; /** * Run a service. This called after {@link Service#start()} * @return the exit code * @throws Throwable any exception to report */ int runService() throws Throwable; }