1 //
2 // ========================================================================
3 // Copyright (c) 1995-2013 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
23 import javax.servlet.ServletException;
24 import javax.servlet.http.HttpServletRequest;
25 import javax.servlet.http.HttpServletResponse;
26
27 import org.eclipse.jetty.server.Handler;
28 import org.eclipse.jetty.server.Request;
29 import org.eclipse.jetty.server.Server;
30
31 /* ------------------------------------------------------------ */
32 /**
33 * A <code>HandlerContainer</code> that allows a hot swap of a wrapped handler.
34 *
35 */
36 public class HotSwapHandler extends AbstractHandlerContainer
37 {
38 private volatile Handler _handler;
39
40 /* ------------------------------------------------------------ */
41 /**
42 *
43 */
44 public HotSwapHandler()
45 {
46 }
47
48 /* ------------------------------------------------------------ */
49 /**
50 * @return Returns the handlers.
51 */
52 public Handler getHandler()
53 {
54 return _handler;
55 }
56
57 /* ------------------------------------------------------------ */
58 /**
59 * @return Returns the handlers.
60 */
61 public Handler[] getHandlers()
62 {
63 return new Handler[]
64 { _handler };
65 }
66
67 /* ------------------------------------------------------------ */
68 /**
69 * @param handler
70 * Set the {@link Handler} which should be wrapped.
71 */
72 public void setHandler(Handler handler)
73 {
74 if (handler == null)
75 throw new IllegalArgumentException("Parameter handler is null.");
76 try
77 {
78 Handler old_handler = _handler;
79 _handler = handler;
80 Server server = getServer();
81 handler.setServer(server);
82 addBean(handler);
83
84 if (server != null)
85 server.getContainer().update(this,old_handler,handler,"handler");
86
87 // if there is an old handler and it was started, stop it
88 if (old_handler != null)
89 {
90 removeBean(old_handler);
91 }
92
93 }
94 catch (Exception e)
95 {
96 throw new RuntimeException(e);
97 }
98 }
99
100 /* ------------------------------------------------------------ */
101 /*
102 * @see org.eclipse.thread.AbstractLifeCycle#doStart()
103 */
104 @Override
105 protected void doStart() throws Exception
106 {
107 super.doStart();
108 }
109
110 /* ------------------------------------------------------------ */
111 /*
112 * @see org.eclipse.thread.AbstractLifeCycle#doStop()
113 */
114 @Override
115 protected void doStop() throws Exception
116 {
117 super.doStop();
118 }
119
120 /* ------------------------------------------------------------ */
121 /*
122 * @see org.eclipse.jetty.server.server.EventHandler#handle(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
123 */
124 public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
125 {
126 if (_handler != null && isStarted())
127 {
128 _handler.handle(target,baseRequest,request,response);
129 }
130 }
131
132 /* ------------------------------------------------------------ */
133 @Override
134 public void setServer(Server server)
135 {
136 Server old_server = getServer();
137 if (server == old_server)
138 return;
139
140 if (isRunning())
141 throw new IllegalStateException(RUNNING);
142
143 super.setServer(server);
144
145 Handler h = getHandler();
146 if (h != null)
147 h.setServer(server);
148
149 if (server != null && server != old_server)
150 server.getContainer().update(this,null,_handler,"handler");
151 }
152
153 /* ------------------------------------------------------------ */
154 @SuppressWarnings(
155 { "rawtypes", "unchecked" })
156 @Override
157 protected Object expandChildren(Object list, Class byClass)
158 {
159 return expandHandler(_handler,list,byClass);
160 }
161
162 /* ------------------------------------------------------------ */
163 @Override
164 public void destroy()
165 {
166 if (!isStopped())
167 throw new IllegalStateException("!STOPPED");
168 Handler child = getHandler();
169 if (child != null)
170 {
171 setHandler(null);
172 child.destroy();
173 }
174 super.destroy();
175 }
176 }