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1   /**
2    * This file Copyright (c) 2008-2013 Magnolia International
3    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
4    *
5    *
6    * This file is dual-licensed under both the Magnolia
7    * Network Agreement and the GNU General Public License.
8    * You may elect to use one or the other of these licenses.
9    *
10   * This file is distributed in the hope that it will be
11   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12   * implied warranty of MERCHANTABILITY or FITNESS FOR A
13   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14   * Redistribution, except as permitted by whichever of the GPL
15   * or MNA you select, is prohibited.
16   *
17   * 1. For the GPL license (GPL), you can redistribute and/or
18   * modify this file under the terms of the GNU General
19   * Public License, Version 3, as published by the Free Software
20   * Foundation.  You should have received a copy of the GNU
21   * General Public License, Version 3 along with this program;
22   * if not, write to the Free Software Foundation, Inc., 51
23   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24   *
25   * 2. For the Magnolia Network Agreement (MNA), this file
26   * and the accompanying materials are made available under the
27   * terms of the MNA which accompanies this distribution, and
28   * is available at http://www.magnolia-cms.com/mna.html
29   *
30   * Any modifications to this file must keep this entire header
31   * intact.
32   *
33   */
34  package info.magnolia.voting.voters;
35  
36  import info.magnolia.context.Context;
37  import info.magnolia.context.MgnlContext;
38  import info.magnolia.context.WebContext;
39  
40  import java.util.ArrayList;
41  import java.util.List;
42  
43  import javax.servlet.http.HttpServletRequest;
44  
45  /**
46   * A voter which checks the user agent header in <code>request</code>
47   * object against a list of allowed and/or rejected user agents.
48   *
49   * @author had
50   * @version $Revision: $ ($Author: $)
51   */
52  public class UserAgentVoter extends AbstractBoolVoter {
53      private static final org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(UserAgentVoter.class);
54  
55      private final List<String> allowed = new ArrayList<String>();
56      private final List<String> rejected = new ArrayList<String>();
57  
58      public List<String> getAllowed() {
59          return allowed;
60      }
61  
62      public void setAllowed(List<String> allowed) {
63          this.allowed.addAll(allowed);
64      }
65  
66      public void addAllowed(String contentType) {
67          allowed.add(contentType);
68      }
69  
70      public List<String> getRejected() {
71          return rejected;
72      }
73  
74      public void setRejected(List<String> rejected) {
75          this.rejected.addAll(rejected);
76      }
77  
78      public void addRejected(String contentType) {
79          rejected.add(contentType);
80      }
81  
82      @Override
83      protected boolean boolVote(Object value) {
84          final HttpServletRequest request;
85          if (value instanceof HttpServletRequest) {
86              request = (HttpServletRequest) value;
87          } else {
88              final Context ctx = MgnlContext.getInstance();
89              if (ctx instanceof WebContext) {
90                  request = ((WebContext) ctx).getRequest();
91              } else {
92                  return false;
93              }
94          }
95  
96          final String userAgent = request.getHeader("User-Agent");
97          // values look like:
98          // Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.4) Gecko/2008111317 Ubuntu/8.04 (hardy) Firefox/3.0.4
99          if (userAgent == null) {
100             log.warn("No user agent on the request, can't vote.");
101             return false;
102         }
103         if (allowed.size() > 0 && !matches(allowed, userAgent)) {
104             return false;
105         }
106         if (rejected.size() > 0 && matches(rejected, userAgent)) {
107             return false;
108         }
109         return true;
110     }
111 
112     /**
113      * Matches obtained user agent against patterns in the list.
114      * @param patterns List of patterns to check.
115      * @param userAgent User Agent value from the request.
116      * @return true if at least one pattern matches the <code>userAgent</code>, false otherwise.
117      */
118     private boolean matches(List patterns, String userAgent) {
119         for (int i = 0; i < patterns.size(); i++) {
120             if (userAgent.matches((String) patterns.get(i))) {
121                 return true;
122             }
123         }
124         return false;
125     }
126 }