001 /** 002 * Copyright (c) 2010 Yahoo! Inc. All rights reserved. 003 * Licensed under the Apache License, Version 2.0 (the "License"); 004 * you may not use this file except in compliance with the License. 005 * You may obtain a copy of the License at 006 * 007 * http://www.apache.org/licenses/LICENSE-2.0 008 * 009 * Unless required by applicable law or agreed to in writing, software 010 * distributed under the License is distributed on an "AS IS" BASIS, 011 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012 * See the License for the specific language governing permissions and 013 * limitations under the License. See accompanying LICENSE file. 014 */ 015 package org.apache.oozie.service; 016 017 018 /** 019 * A service is component managed by the {@link Services} singleton. 020 */ 021 public interface Service { 022 023 /** 024 * Prefix for all services configuration properties. 025 */ 026 public static final String CONF_PREFIX = "oozie.service."; 027 028 /** 029 * Initialize the service. <p/> Invoked by the {@link Service} singleton at start up time. 030 * 031 * @param services services singleton initializing the service. 032 * @throws ServiceException thrown if the service could not initialize. 033 */ 034 public void init(Services services) throws ServiceException; 035 036 /** 037 * Destroy the service. <p/> Invoked by the {@link Service} singleton at shutdown time. 038 */ 039 public void destroy(); 040 041 /** 042 * Return the public interface of the service. <p/> Services are retrieved by its public interface. Specializations 043 * of services must return the public interface. 044 * 045 * @return the interface of the service. 046 */ 047 public Class<? extends Service> getInterface(); 048 049 }