1 /* 2 * $Id$ 3 * 4 * Licensed to the Apache Software Foundation (ASF) under one 5 * or more contributor license agreements. See the NOTICE file 6 * distributed with this work for additional information 7 * regarding copyright ownership. The ASF licenses this file 8 * to you under the Apache License, Version 2.0 (the 9 * "License"); you may not use this file except in compliance 10 * with the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, 15 * software distributed under the License is distributed on an 16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 17 * KIND, either express or implied. See the License for the 18 * specific language governing permissions and limitations 19 * under the License. 20 */ 21 package org.apache.struts.action; 22 23 import org.apache.struts.config.ModuleConfig; 24 25 import jakarta.servlet.ServletException; 26 27 /** 28 * <p>A <strong>PlugIn</strong> is a configuration wrapper for a 29 * module-specific resource or service that needs to be notified about 30 * application startup and application shutdown events (corresponding to when 31 * the container calls <code>init</code> and <code>destroy</code> on the 32 * corresponding {@link ActionServlet} instance). <code>PlugIn</code> objects 33 * can be configured in the <code>struts-config.xml</code> file, without the 34 * need to subclass {@link ActionServlet} simply to perform application 35 * lifecycle activities.</p> 36 * 37 * <p>Implementations of this interface must supply a zero-argument 38 * constructor for use by {@link ActionServlet}. Configuration can be 39 * accomplished by providing standard JavaBeans property setter methods, which 40 * will all have been called before the <code>init()</code> method is 41 * invoked.</p> 42 * 43 * <p>This interface can be applied to any class, including an Action 44 * subclass. </p> 45 * 46 * @version $Rev$ $Date: 2005-05-14 01:09:32 -0400 (Sat, 14 May 2005) 47 * $ 48 * @since Struts 1.1 49 */ 50 public interface PlugIn { 51 /** 52 * <p>Receive notification that our owning module is being shut down.</p> 53 */ 54 void destroy(); 55 56 /** 57 * <p>Receive notification that the specified module is being started 58 * up.</p> 59 * 60 * @param servlet ActionServlet that is managing all the modules in this 61 * web application 62 * @param config ModuleConfig for the module with which this plug-in is 63 * associated 64 * @throws ServletException if this <code>PlugIn</code> cannot be 65 * successfully initialized 66 */ 67 void init(ActionServlet servlet, ModuleConfig config) 68 throws ServletException; 69 }