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1   /*
2    * Copyright (c) 2002-2022, City of Paris
3    * All rights reserved.
4    *
5    * Redistribution and use in source and binary forms, with or without
6    * modification, are permitted provided that the following conditions
7    * are met:
8    *
9    *  1. Redistributions of source code must retain the above copyright notice
10   *     and the following disclaimer.
11   *
12   *  2. Redistributions in binary form must reproduce the above copyright notice
13   *     and the following disclaimer in the documentation and/or other materials
14   *     provided with the distribution.
15   *
16   *  3. Neither the name of 'Mairie de Paris' nor 'Lutece' nor the names of its
17   *     contributors may be used to endorse or promote products derived from
18   *     this software without specific prior written permission.
19   *
20   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
24   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30   * POSSIBILITY OF SUCH DAMAGE.
31   *
32   * License 1.0
33   */
34  package fr.paris.lutece.portal.web.encoding;
35  
36  import java.util.Locale;
37  import javax.servlet.http.HttpServletResponse;
38  
39  /**
40   * This class provides a Wrapper of an Http response that manage a correct UTF-8 encoding
41   *
42   */
43  public class EncodingServletResponse extends javax.servlet.http.HttpServletResponseWrapper
44  {
45      private static final String RESPONSE_ENCODING = "UTF-8";
46      private boolean _bEncodingSpecified;
47  
48      /**
49       * Constructor
50       * 
51       * @param response
52       *            The HTTP response
53       */
54      public EncodingServletResponse( HttpServletResponse response )
55      {
56          super( response );
57      }
58  
59      /**
60       * Sets the content type
61       * 
62       * @param type
63       *            The content type
64       */
65      @Override
66      public void setContentType( String type )
67      {
68          String explicitType = type;
69  
70          // If a specific encoding has not already been set by the app,
71          // let's see if this is a call to specify it. If the content
72          // type doesn't explicitly set an encoding, make it UTF-8.
73          if ( !_bEncodingSpecified )
74          {
75              String lowerType = type.toLowerCase( Locale.ENGLISH );
76  
77              // See if this is a call to explicitly set the character encoding.
78              if ( !lowerType.contains( "charset" ) )
79              {
80                  // If no character encoding is specified, we still need to
81                  // ensure the app is specifying text content.
82                  if ( lowerType.startsWith( "text/" ) )
83                  {
84                      // App is sending a text response, but no encoding
85                      // is specified, so we'll force it to UTF-8.
86                      explicitType = type + "; charset=" + RESPONSE_ENCODING;
87                  }
88              }
89              else
90              {
91                  // App picked a specific encoding, so let's make
92                  // sure we don't override it.
93                  _bEncodingSpecified = true;
94              }
95          }
96  
97          // Delegate to supertype to record encoding.
98          super.setContentType( explicitType );
99      }
100 }