1   /**
2    * Copyright (c) 2000-2007 Liferay, Inc. All rights reserved.
3    *
4    * Permission is hereby granted, free of charge, to any person obtaining a copy
5    * of this software and associated documentation files (the "Software"), to deal
6    * in the Software without restriction, including without limitation the rights
7    * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8    * copies of the Software, and to permit persons to whom the Software is
9    * furnished to do so, subject to the following conditions:
10   *
11   * The above copyright notice and this permission notice shall be included in
12   * all copies or substantial portions of the Software.
13   *
14   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20   * SOFTWARE.
21   */
22  
23  package com.liferay.filters.doubleclick;
24  
25  import com.liferay.util.servlet.filters.CacheResponse;
26  import com.liferay.util.servlet.filters.CacheResponseData;
27  import com.liferay.util.servlet.filters.CacheResponseUtil;
28  
29  import java.io.IOException;
30  import java.io.Serializable;
31  
32  import javax.servlet.FilterChain;
33  import javax.servlet.ServletException;
34  import javax.servlet.http.HttpServletRequest;
35  import javax.servlet.http.HttpServletResponse;
36  
37  /**
38   * <a href="DoubleClickController.java.html"><b><i>View Source</i></b></a>
39   *
40   * @author Olaf Fricke
41   * @author Brian Wing Shun Chan
42   *
43   */
44  public class DoubleClickController implements Serializable {
45  
46      public void control(
47              HttpServletRequest req, HttpServletResponse res, FilterChain chain)
48          throws IOException, ServletException {
49  
50          boolean firstRequest = false;
51  
52          CacheResponse cacheResponse = null;
53  
54          synchronized (this) {
55              if (_cacheResponse == null) {
56                  firstRequest = true;
57  
58                  _cacheResponse = new CacheResponse(
59                      res, DoubleClickFilter.ENCODING);
60                  _throwable = null;
61              }
62  
63              cacheResponse = _cacheResponse;
64          }
65  
66          if (firstRequest) {
67              try {
68                  chain.doFilter(req, _cacheResponse);
69              }
70              catch (Throwable t) {
71                  _throwable = t;
72              }
73              finally {
74                  synchronized (this) {
75                      _cacheResponse = null;
76  
77                      notifyAll();
78                  }
79              }
80          }
81          else {
82              synchronized (this) {
83                  while (_cacheResponse != null) {
84                      try {
85                          wait();
86                      }
87                      catch (InterruptedException ie) {
88                          Thread.currentThread().interrupt();
89                      }
90                  }
91              }
92          }
93  
94          if (_throwable != null) {
95              try {
96                  throw _throwable;
97              }
98              catch (IOException ioe) {
99                  throw ioe;
100             }
101             catch (ServletException se) {
102                 throw se;
103             }
104             catch (RuntimeException re) {
105                 throw re;
106             }
107             catch (Error e) {
108                 throw e;
109             }
110             catch (Throwable t) {
111                 throw new RuntimeException(t);
112             }
113         }
114 
115         CacheResponseData data = new CacheResponseData(
116             cacheResponse.getData(), cacheResponse.getContentType(),
117             cacheResponse.getHeaders());
118 
119         CacheResponseUtil.write(res, data);
120     }
121 
122     private CacheResponse _cacheResponse;
123     private Throwable _throwable;
124 
125 }