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.servlet.HttpHeaders;
26  
27  import java.util.Arrays;
28  
29  import javax.servlet.http.HttpServletRequest;
30  import javax.servlet.http.HttpServletResponse;
31  
32  /**
33   * <a href="ETagUtil.java.html"><b><i>View Source</i></b></a>
34   *
35   * @author Brian Wing Shun Chan
36   *
37   */
38  public class ETagUtil {
39  
40      public static boolean processETag(
41          HttpServletRequest request, HttpServletResponse response,
42          byte[] bytes) {
43  
44          boolean continueProcessingFilter = false;
45  
46          String eTag = Integer.toHexString(Arrays.hashCode(bytes));
47  
48          response.setHeader(HttpHeaders.ETAG, eTag);
49  
50          String ifNoneMatch = request.getHeader(HttpHeaders.IF_NONE_MATCH);
51  
52          if (eTag.equals(ifNoneMatch)) {
53              response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
54  
55              continueProcessingFilter = true;
56          }
57  
58          return continueProcessingFilter;
59      }
60  
61      public static boolean processETag(
62          HttpServletRequest request, HttpServletResponse response, String s) {
63  
64          return processETag(request, response, s.getBytes());
65      }
66  
67  }