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.LazyList;
26 import org.eclipse.jetty.util.component.LifeCycle;
27
28 /* ------------------------------------------------------------ */
29 /** A <code>HandlerWrapper</code> acts as a {@link Handler} but delegates the {@link Handler#handle handle} method and
30 * {@link LifeCycle life cycle} events to a delegate. This is primarily used to implement the <i>Decorator</i> pattern.
31 *
32 */
33 public class HandlerWrapper extends AbstractHandlerContainer
34 {
35 protected Handler _handler;
36
37 /* ------------------------------------------------------------ */
38 /**
39 *
40 */
41 public HandlerWrapper()
42 {
43 }
44
45 /* ------------------------------------------------------------ */
46 /**
47 * @return Returns the handlers.
48 */
49 public Handler getHandler()
50 {
51 return _handler;
52 }
53
54 /* ------------------------------------------------------------ */
55 /**
56 * @return Returns the handlers.
57 */
58 public Handler[] getHandlers()
59 {
60 return new Handler[] {_handler};
61 }
62
63 /* ------------------------------------------------------------ */
64 /**
65 * @param handler Set the {@link Handler} which should be wrapped.
66 */
67 public void setHandler(Handler handler)
68 {
69 if (isStarted())
70 throw new IllegalStateException(STARTED);
71
72 Handler old_handler = _handler;
73
74 if (getServer()!=null)
75 getServer().getContainer().update(this, old_handler, handler, "handler");
76
77 if (handler!=null)
78 {
79 handler.setServer(getServer());
80 }
81
82 _handler = handler;
83 }
84
85 /* ------------------------------------------------------------ */
86 /*
87 * @see org.eclipse.thread.AbstractLifeCycle#doStart()
88 */
89 @Override
90 protected void doStart() throws Exception
91 {
92 if (_handler!=null)
93 _handler.start();
94 super.doStart();
95 }
96
97 /* ------------------------------------------------------------ */
98 /*
99 * @see org.eclipse.thread.AbstractLifeCycle#doStop()
100 */
101 @Override
102 protected void doStop() throws Exception
103 {
104 super.doStop();
105 if (_handler!=null)
106 _handler.stop();
107 }
108
109 /* ------------------------------------------------------------ */
110 public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
111 {
112 if (_handler!=null && isStarted())
113 {
114 _handler.handle(target,baseRequest, request, response);
115 }
116 }
117
118
119 /* ------------------------------------------------------------ */
120 @Override
121 public void setServer(Server server)
122 {
123 Server old_server=getServer();
124 if (server==old_server)
125 return;
126
127 if (isStarted())
128 throw new IllegalStateException(STARTED);
129
130 super.setServer(server);
131
132 Handler h=getHandler();
133 if (h!=null)
134 h.setServer(server);
135
136 if (server!=null && server!=old_server)
137 server.getContainer().update(this, null,_handler, "handler");
138 }
139
140
141 /* ------------------------------------------------------------ */
142 @Override
143 protected Object expandChildren(Object list, Class byClass)
144 {
145 return expandHandler(_handler,list,byClass);
146 }
147
148 /* ------------------------------------------------------------ */
149 public <H extends Handler> H getNestedHandlerByClass(Class<H> byclass)
150 {
151 HandlerWrapper h=this;
152 while (h!=null)
153 {
154 if (byclass.isInstance(h))
155 return (H)h;
156 Handler w = h.getHandler();
157 if (w instanceof HandlerWrapper)
158 h=(HandlerWrapper)w;
159 else break;
160 }
161 return null;
162
163 }
164
165
166 }