| /** |
| * 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.server; |
| |
| /** |
| * Service interface for components to be managed by the {@link Server} class. |
| */ |
| public interface Service { |
| |
| /** |
| * Initializes the service. This method is called once, when the |
| * {@link Server} owning the service is being initialized. |
| * |
| * @param server the server initializing the service, give access to the |
| * server context. |
| * |
| * @throws ServiceException thrown if the service could not be initialized. |
| */ |
| public void init(Server server) throws ServiceException; |
| |
| /** |
| * Post initializes the service. This method is called by the |
| * {@link Server} after all services of the server have been initialized. |
| * |
| * @throws ServiceException thrown if the service could not be |
| * post-initialized. |
| */ |
| public void postInit() throws ServiceException; |
| |
| /** |
| * Destroy the services. This method is called once, when the |
| * {@link Server} owning the service is being destroyed. |
| */ |
| public void destroy(); |
| |
| /** |
| * Returns the service dependencies of this service. The service will be |
| * instantiated only if all the service dependencies are already initialized. |
| * |
| * @return the service dependencies. |
| */ |
| public Class[] getServiceDependencies(); |
| |
| /** |
| * Returns the interface implemented by this service. This interface is used |
| * the {@link Server} when the {@link Server#get(Class)} method is used to |
| * retrieve a service. |
| * |
| * @return the interface that identifies the service. |
| */ |
| public Class getInterface(); |
| |
| /** |
| * Notification callback when the server changes its status. |
| * |
| * @param oldStatus old server status. |
| * @param newStatus new server status. |
| * |
| * @throws ServiceException thrown if the service could not process the status change. |
| */ |
| public void serverStatusChange(Server.Status oldStatus, Server.Status newStatus) throws ServiceException; |
| |
| } |