1 //
2 // ========================================================================
3 // Copyright (c) 1995-2012 Mort Bay Consulting Pty. Ltd.
4 // ------------------------------------------------------------------------
5 // All rights reserved. This program and the accompanying materials
6 // are made available under the terms of the Eclipse Public License v1.0
7 // and Apache License v2.0 which accompanies this distribution.
8 //
9 // The Eclipse Public License is available at
10 // http://www.eclipse.org/legal/epl-v10.html
11 //
12 // The Apache License v2.0 is available at
13 // http://www.opensource.org/licenses/apache2.0.php
14 //
15 // You may elect to redistribute this code under either of these licenses.
16 // ========================================================================
17 //
18
19 package org.eclipse.jetty.server.handler;
20
21 import java.io.IOException;
22 import java.util.List;
23
24 import javax.servlet.ServletException;
25 import javax.servlet.http.HttpServletRequest;
26 import javax.servlet.http.HttpServletResponse;
27
28 import org.eclipse.jetty.server.Handler;
29 import org.eclipse.jetty.server.Request;
30 import org.eclipse.jetty.server.Server;
31
32 /* ------------------------------------------------------------ */
33 /**
34 * A <code>HandlerContainer</code> that allows a hot swap of a wrapped handler.
35 *
36 */
37 public class HotSwapHandler extends AbstractHandlerContainer
38 {
39 private volatile Handler _handler;
40
41 /* ------------------------------------------------------------ */
42 /**
43 *
44 */
45 public HotSwapHandler()
46 {
47 }
48
49 /* ------------------------------------------------------------ */
50 /**
51 * @return Returns the handlers.
52 */
53 public Handler getHandler()
54 {
55 return _handler;
56 }
57
58 /* ------------------------------------------------------------ */
59 /**
60 * @return Returns the handlers.
61 */
62 @Override
63 public Handler[] getHandlers()
64 {
65 return new Handler[]
66 { _handler };
67 }
68
69 /* ------------------------------------------------------------ */
70 /**
71 * @param handler
72 * Set the {@link Handler} which should be wrapped.
73 */
74 public void setHandler(Handler handler)
75 {
76 if (handler == null)
77 throw new IllegalArgumentException("Parameter handler is null.");
78 try
79 {
80 updateBean(_handler,handler);
81 _handler=handler;
82 Server server = getServer();
83 handler.setServer(server);
84
85 }
86 catch (Exception e)
87 {
88 throw new RuntimeException(e);
89 }
90 }
91
92 /* ------------------------------------------------------------ */
93 /*
94 * @see org.eclipse.thread.AbstractLifeCycle#doStart()
95 */
96 @Override
97 protected void doStart() throws Exception
98 {
99 super.doStart();
100 }
101
102 /* ------------------------------------------------------------ */
103 /*
104 * @see org.eclipse.thread.AbstractLifeCycle#doStop()
105 */
106 @Override
107 protected void doStop() throws Exception
108 {
109 super.doStop();
110 }
111
112 /* ------------------------------------------------------------ */
113 /*
114 * @see org.eclipse.jetty.server.server.EventHandler#handle(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
115 */
116 @Override
117 public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
118 {
119 if (_handler != null && isStarted())
120 {
121 _handler.handle(target,baseRequest,request,response);
122 }
123 }
124
125 /* ------------------------------------------------------------ */
126 @Override
127 public void setServer(Server server)
128 {
129 if (isRunning())
130 throw new IllegalStateException(RUNNING);
131
132 super.setServer(server);
133
134 Handler h = getHandler();
135 if (h != null)
136 h.setServer(server);
137 }
138
139 /* ------------------------------------------------------------ */
140 @Override
141 protected void expandChildren(List<Handler> list, Class<?> byClass)
142 {
143 expandHandler(_handler,list,byClass);
144 }
145
146 /* ------------------------------------------------------------ */
147 @Override
148 public void destroy()
149 {
150 if (!isStopped())
151 throw new IllegalStateException("!STOPPED");
152 Handler child = getHandler();
153 if (child != null)
154 {
155 setHandler(null);
156 child.destroy();
157 }
158 super.destroy();
159 }
160 }