1   /**
2    * Copyright (c) 2000-2009 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.portal.servlet.filters.etag;
24  
25  import com.liferay.portal.kernel.util.ParamUtil;
26  import com.liferay.portal.kernel.util.StringPool;
27  import com.liferay.portal.servlet.filters.BasePortalFilter;
28  import com.liferay.util.servlet.filters.CacheResponse;
29  import com.liferay.util.servlet.filters.CacheResponseData;
30  import com.liferay.util.servlet.filters.CacheResponseUtil;
31  
32  import javax.servlet.FilterChain;
33  import javax.servlet.http.HttpServletRequest;
34  import javax.servlet.http.HttpServletResponse;
35  
36  /**
37   * <a href="ETagFilter.java.html"><b><i>View Source</i></b></a>
38   *
39   * @author Eduardo Lundgren
40   * @author Brian Wing Shun Chan
41   * @author Raymond Augé
42   */
43  public class ETagFilter extends BasePortalFilter {
44  
45      protected void processFilter(
46              HttpServletRequest request, HttpServletResponse response,
47              FilterChain filterChain)
48          throws Exception {
49  
50          boolean etag = ParamUtil.getBoolean(request, _ETAG, true);
51  
52          if (etag) {
53              CacheResponse cacheResponse = new CacheResponse(
54                  response, StringPool.UTF8);
55  
56              processFilter(
57                  ETagFilter.class, request, cacheResponse, filterChain);
58  
59              CacheResponseData cacheResponseData = new CacheResponseData(
60                  cacheResponse.getData(), cacheResponse.getContentType(),
61                  cacheResponse.getHeaders());
62  
63              if (!ETagUtil.processETag(
64                      request, response, cacheResponse.getData())) {
65  
66                  CacheResponseUtil.write(response, cacheResponseData);
67              }
68          }
69          else {
70              processFilter(
71                  ETagFilter.class, request, response, filterChain);
72          }
73      }
74  
75      private static final String _ETAG = "etag";
76  
77  }