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 if (_handler==null)
61 return new Handler[0];
62 return new Handler[] {_handler};
63 }
64
65 /* ------------------------------------------------------------ */
66 /**
67 * @param handler Set the {@link Handler} which should be wrapped.
68 */
69 public void setHandler(Handler handler)
70 {
71 if (isStarted())
72 throw new IllegalStateException(STARTED);
73
74 Handler old_handler = _handler;
75
76 if (getServer()!=null)
77 getServer().getContainer().update(this, old_handler, handler, "handler");
78
79 if (handler!=null)
80 {
81 handler.setServer(getServer());
82 }
83
84 _handler = handler;
85 }
86
87 /* ------------------------------------------------------------ */
88 /*
89 * @see org.eclipse.thread.AbstractLifeCycle#doStart()
90 */
91 @Override
92 protected void doStart() throws Exception
93 {
94 if (_handler!=null)
95 _handler.start();
96 super.doStart();
97 }
98
99 /* ------------------------------------------------------------ */
100 /*
101 * @see org.eclipse.thread.AbstractLifeCycle#doStop()
102 */
103 @Override
104 protected void doStop() throws Exception
105 {
106 super.doStop();
107 if (_handler!=null)
108 _handler.stop();
109 }
110
111 /* ------------------------------------------------------------ */
112 public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
113 {
114 if (_handler!=null && isStarted())
115 {
116 _handler.handle(target,baseRequest, request, response);
117 }
118 }
119
120
121 /* ------------------------------------------------------------ */
122 @Override
123 public void setServer(Server server)
124 {
125 Server old_server=getServer();
126 if (server==old_server)
127 return;
128
129 if (isStarted())
130 throw new IllegalStateException(STARTED);
131
132 super.setServer(server);
133
134 Handler h=getHandler();
135 if (h!=null)
136 h.setServer(server);
137
138 if (server!=null && server!=old_server)
139 server.getContainer().update(this, null,_handler, "handler");
140 }
141
142
143 /* ------------------------------------------------------------ */
144 @Override
145 protected Object expandChildren(Object list, Class byClass)
146 {
147 return expandHandler(_handler,list,byClass);
148 }
149
150 /* ------------------------------------------------------------ */
151 public <H extends Handler> H getNestedHandlerByClass(Class<H> byclass)
152 {
153 HandlerWrapper h=this;
154 while (h!=null)
155 {
156 if (byclass.isInstance(h))
157 return (H)h;
158 Handler w = h.getHandler();
159 if (w instanceof HandlerWrapper)
160 h=(HandlerWrapper)w;
161 else break;
162 }
163 return null;
164
165 }
166
167
168 }