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1   //
2   //  ========================================================================
3   //  Copyright (c) 1995-2014 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.concurrent.CountDownLatch;
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  import org.eclipse.jetty.util.LazyList;
32  import org.eclipse.jetty.util.MultiException;
33  
34  /* ------------------------------------------------------------ */
35  /** A collection of handlers.  
36   * <p>
37   * The default implementations  calls all handlers in list order, 
38   * regardless of the response status or exceptions. Derived implementation
39   * may alter the order or the conditions of calling the contained 
40   * handlers.
41   * <p>
42   * 
43   * @org.apache.xbean.XBean
44   */
45  public class HandlerCollection extends AbstractHandlerContainer
46  {
47      private final boolean _mutableWhenRunning;
48      private volatile Handler[] _handlers;
49      private boolean _parallelStart=false; 
50  
51      /* ------------------------------------------------------------ */
52      public HandlerCollection()
53      {
54          _mutableWhenRunning=false;
55      }
56      
57      /* ------------------------------------------------------------ */
58      public HandlerCollection(boolean mutableWhenRunning)
59      {
60          _mutableWhenRunning=mutableWhenRunning;
61      }
62  
63      /* ------------------------------------------------------------ */
64      /**
65       * @return Returns the handlers.
66       */
67      public Handler[] getHandlers()
68      {
69          return _handlers;
70      }
71      
72      /* ------------------------------------------------------------ */
73      /**
74       * 
75       * @param handlers The handlers to set.
76       */
77      public void setHandlers(Handler[] handlers)
78      {
79          if (!_mutableWhenRunning && isStarted())
80              throw new IllegalStateException(STARTED);
81          
82          Handler [] old_handlers = _handlers==null?null:_handlers.clone();
83          _handlers = handlers;
84          
85          Server server = getServer();
86          MultiException mex = new MultiException();
87          for (int i=0;handlers!=null && i<handlers.length;i++)
88          {
89              if (handlers[i].getServer()!=server)
90                  handlers[i].setServer(server);
91          }
92  
93          if (getServer()!=null)
94              getServer().getContainer().update(this, old_handlers, handlers, "handler");
95          
96          // stop old handlers
97          for (int i=0;old_handlers!=null && i<old_handlers.length;i++)
98          {
99              if (old_handlers[i]!=null)
100             {
101                 try
102                 {
103                     if (old_handlers[i].isStarted())
104                         old_handlers[i].stop();
105                 }
106                 catch (Throwable e)
107                 {
108                     mex.add(e);
109                 }
110             }
111         }
112                 
113         mex.ifExceptionThrowRuntime();
114     }
115     
116 
117     
118     /* ------------------------------------------------------------ */
119     /** Get the parrallelStart.
120      * @return true if the contained handlers are started in parallel.
121      */
122     public boolean isParallelStart()
123     {
124         return _parallelStart;
125     }
126 
127 
128 
129     /* ------------------------------------------------------------ */
130     /** Set the parallelStart.
131      * @param parallelStart If true, contained handlers are started in parallel.
132      */
133     public void setParallelStart(boolean parallelStart)
134     {
135         this._parallelStart = parallelStart;
136     }
137 
138 
139     /* ------------------------------------------------------------ */
140     /**
141      * @see Handler#handle(String, Request, HttpServletRequest, HttpServletResponse)
142      */
143     public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) 
144         throws IOException, ServletException
145     {
146         if (_handlers!=null && isStarted())
147         {
148             MultiException mex=null;
149             
150             for (int i=0;i<_handlers.length;i++)
151             {
152                 try
153                 {
154                     _handlers[i].handle(target,baseRequest, request, response);
155                 }
156                 catch(IOException e)
157                 {
158                     throw e;
159                 }
160                 catch(RuntimeException e)
161                 {
162                     throw e;
163                 }
164                 catch(Exception e)
165                 {
166                     if (mex==null)
167                         mex=new MultiException();
168                     mex.add(e);
169                 }
170             }
171             if (mex!=null)
172             {
173                 if (mex.size()==1)
174                     throw new ServletException(mex.getThrowable(0));
175                 else
176                     throw new ServletException(mex);
177             }
178             
179         }    
180     }
181 
182     /* ------------------------------------------------------------ */
183     /* 
184      * @see org.eclipse.jetty.server.server.handler.AbstractHandler#doStart()
185      */
186     @Override
187     protected void doStart() throws Exception
188     {
189         final MultiException mex=new MultiException();
190         if (_handlers!=null)
191         {
192             if (_parallelStart)
193             {
194                 final CountDownLatch latch = new CountDownLatch(_handlers.length);
195                 final ClassLoader loader = Thread.currentThread().getContextClassLoader();
196                 for (int i=0;i<_handlers.length;i++)
197                 {
198                     final int h=i;
199                     getServer().getThreadPool().dispatch(
200                             new Runnable()
201                             {
202                                 public void run()
203                                 {
204                                     ClassLoader orig = Thread.currentThread().getContextClassLoader();
205                                     try
206                                     {
207                                         Thread.currentThread().setContextClassLoader(loader);
208                                         _handlers[h].start();
209                                     }
210                                     catch(Throwable e)
211                                     {
212                                         mex.add(e);
213                                     }
214                                     finally
215                                     {
216                                         Thread.currentThread().setContextClassLoader(orig);
217                                         latch.countDown();
218                                     }
219                                 }
220                             }
221                     );
222                 }
223                 latch.await();
224             }
225             else
226             {
227                 for (int i=0;i<_handlers.length;i++)
228                 {
229                     try{_handlers[i].start();}
230                     catch(Throwable e){mex.add(e);}
231                 }
232             }
233         }
234         super.doStart();
235         mex.ifExceptionThrow();
236     }
237 
238     /* ------------------------------------------------------------ */
239     /* 
240      * @see org.eclipse.jetty.server.server.handler.AbstractHandler#doStop()
241      */
242     @Override
243     protected void doStop() throws Exception
244     {
245         MultiException mex=new MultiException();
246         try { super.doStop(); } catch(Throwable e){mex.add(e);}
247         if (_handlers!=null)
248         {
249             for (int i=_handlers.length;i-->0;)
250                 try{_handlers[i].stop();}catch(Throwable e){mex.add(e);}
251         }
252         mex.ifExceptionThrow();
253     }
254     
255     /* ------------------------------------------------------------ */
256     @Override
257     public void setServer(Server server)
258     {
259         if (isStarted())
260             throw new IllegalStateException(STARTED);
261         
262         Server old_server=getServer();
263         
264         super.setServer(server);
265 
266         Handler[] h=getHandlers();
267         for (int i=0;h!=null && i<h.length;i++)
268             h[i].setServer(server);
269         
270         if (server!=null && server!=old_server)
271             server.getContainer().update(this, null,_handlers, "handler");
272         
273     }
274 
275     /* ------------------------------------------------------------ */
276     /* Add a handler.
277      * This implementation adds the passed handler to the end of the existing collection of handlers. 
278      * @see org.eclipse.jetty.server.server.HandlerContainer#addHandler(org.eclipse.jetty.server.server.Handler)
279      */
280     public void addHandler(Handler handler)
281     {
282         setHandlers((Handler[])LazyList.addToArray(getHandlers(), handler, Handler.class));
283     }
284     
285     /* ------------------------------------------------------------ */
286     public void removeHandler(Handler handler)
287     {
288         Handler[] handlers = getHandlers();
289         
290         if (handlers!=null && handlers.length>0 )
291             setHandlers((Handler[])LazyList.removeFromArray(handlers, handler));
292     }
293 
294     /* ------------------------------------------------------------ */
295     @Override
296     protected Object expandChildren(Object list, Class byClass)
297     {
298         Handler[] handlers = getHandlers();
299         for (int i=0;handlers!=null && i<handlers.length;i++)
300             list=expandHandler(handlers[i], list, byClass);
301         return list;
302     }
303 
304     /* ------------------------------------------------------------ */
305     @Override
306     public void destroy()
307     {
308         if (!isStopped())
309             throw new IllegalStateException("!STOPPED");
310         Handler[] children=getChildHandlers();
311         setHandlers(null);
312         for (Handler child: children)
313             child.destroy();
314         super.destroy();
315     }
316 }