1 // ========================================================================
2 // Copyright (c) 2004-2009 Mort Bay Consulting Pty. Ltd.
3 // ------------------------------------------------------------------------
4 // All rights reserved. This program and the accompanying materials
5 // are made available under the terms of the Eclipse Public License v1.0
6 // and Apache License v2.0 which accompanies this distribution.
7 // The Eclipse Public License is available at
8 // http://www.eclipse.org/legal/epl-v10.html
9 // The Apache License v2.0 is available at
10 // http://www.opensource.org/licenses/apache2.0.php
11 // You may elect to redistribute this code under either of these licenses.
12 // ========================================================================
13
14 package org.eclipse.jetty.server.handler;
15
16 import java.io.IOException;
17
18 import javax.servlet.ServletException;
19 import javax.servlet.http.HttpServletRequest;
20 import javax.servlet.http.HttpServletResponse;
21
22 import org.eclipse.jetty.server.Handler;
23 import org.eclipse.jetty.server.Request;
24 import org.eclipse.jetty.server.Server;
25 import org.eclipse.jetty.util.component.LifeCycle;
26
27 /* ------------------------------------------------------------ */
28 /** A <code>HandlerWrapper</code> acts as a {@link Handler} but delegates the {@link Handler#handle handle} method and
29 * {@link LifeCycle life cycle} events to a delegate. This is primarily used to implement the <i>Decorator</i> pattern.
30 *
31 */
32 public class HandlerWrapper extends AbstractHandlerContainer
33 {
34 protected Handler _handler;
35
36 /* ------------------------------------------------------------ */
37 /**
38 *
39 */
40 public HandlerWrapper()
41 {
42 }
43
44 /* ------------------------------------------------------------ */
45 /**
46 * @return Returns the handlers.
47 */
48 public Handler getHandler()
49 {
50 return _handler;
51 }
52
53 /* ------------------------------------------------------------ */
54 /**
55 * @return Returns the handlers.
56 */
57 public Handler[] getHandlers()
58 {
59 return new Handler[] {_handler};
60 }
61
62 /* ------------------------------------------------------------ */
63 /**
64 * @param handler Set the {@link Handler} which should be wrapped.
65 */
66 public void setHandler(Handler handler)
67 {
68 if (isStarted())
69 throw new IllegalStateException(STARTED);
70
71 Handler old_handler = _handler;
72
73 if (getServer()!=null)
74 getServer().getContainer().update(this, old_handler, handler, "handler");
75
76 if (handler!=null)
77 {
78 handler.setServer(getServer());
79 }
80
81 _handler = handler;
82 }
83
84 /* ------------------------------------------------------------ */
85 /*
86 * @see org.eclipse.thread.AbstractLifeCycle#doStart()
87 */
88 @Override
89 protected void doStart() throws Exception
90 {
91 if (_handler!=null)
92 _handler.start();
93 super.doStart();
94 }
95
96 /* ------------------------------------------------------------ */
97 /*
98 * @see org.eclipse.thread.AbstractLifeCycle#doStop()
99 */
100 @Override
101 protected void doStop() throws Exception
102 {
103 super.doStop();
104 if (_handler!=null)
105 _handler.stop();
106 }
107
108 /* ------------------------------------------------------------ */
109 public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
110 {
111 if (_handler!=null && isStarted())
112 {
113 _handler.handle(target,baseRequest, request, response);
114 }
115 }
116
117
118 /* ------------------------------------------------------------ */
119 @Override
120 public void setServer(Server server)
121 {
122 Server old_server=getServer();
123 if (server==old_server)
124 return;
125
126 if (isStarted())
127 throw new IllegalStateException(STARTED);
128
129 super.setServer(server);
130
131 Handler h=getHandler();
132 if (h!=null)
133 h.setServer(server);
134
135 if (server!=null && server!=old_server)
136 server.getContainer().update(this, null,_handler, "handler");
137 }
138
139
140 /* ------------------------------------------------------------ */
141 @Override
142 protected Object expandChildren(Object list, Class byClass)
143 {
144 return expandHandler(_handler,list,byClass);
145 }
146
147
148 }