01: /*
02: * $Id: PlugIn.java 471754 2006-11-06 14:55:09Z husted $
03: *
04: * Licensed to the Apache Software Foundation (ASF) under one
05: * or more contributor license agreements. See the NOTICE file
06: * distributed with this work for additional information
07: * regarding copyright ownership. The ASF licenses this file
08: * to you under the Apache License, Version 2.0 (the
09: * "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 javax.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: 471754 $ $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: }
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