Class SetCharacterEncodingFilter

java.lang.Object
org.apache.catalina.filters.FilterBase
org.apache.catalina.filters.SetCharacterEncodingFilter
All Implemented Interfaces:
Filter
public class SetCharacterEncodingFilter extends FilterBase

Example filter that sets the character encoding to be used in parsing the incoming request, either unconditionally or only if the client did not specify a character encoding. Configuration of this filter is based on the following initialization parameters:

  • encoding - The character encoding to be configured for this request, either conditionally or unconditionally based on the ignore initialization parameter. This parameter is required, so there is no default.
  • ignore - If set to "true", any character encoding specified by the client is ignored, and the value returned by the selectEncoding() method is set. If set to "false, selectEncoding() is called only if the client has not already specified an encoding. By default, this parameter is set to "false".

Although this filter can be used unchanged, it is also easy to subclass it and make the selectEncoding() method more intelligent about what encoding to choose, based on characteristics of the incoming request (such as the values of the Accept-Language and User-Agent headers, or a value stashed in the current user's session).

  • Constructor Details

    • SetCharacterEncodingFilter

      public SetCharacterEncodingFilter()
      Default constructor.

  • Method Details

    • setEncoding

      public void setEncoding(String encoding)
      Sets the character encoding to be configured for requests.
      Parameters:
      encoding - the character encoding

    • getEncoding

      public String getEncoding()
      Returns the character encoding configured for this filter.
      Returns:
      the character encoding

    • setIgnore

      public void setIgnore(boolean ignore)
      Sets whether to ignore any character encoding specified by the client.
      Parameters:
      ignore - true to ignore client-specified encoding

    • isIgnore

      public boolean isIgnore()
      Returns whether client-specified character encodings are ignored.
      Returns:
      true if client encodings are ignored

    • doFilter

      public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException
      Select and set (if specified) the character encoding to be used to interpret request parameters for this request.
      Parameters:
      request - The servlet request we are processing
      response - The servlet response we are creating
      chain - The filter chain we are processing
      Throws:
      IOException - if an input/output error occurs
      ServletException - if a servlet error occurs

    • getLogger

      protected Log getLogger()
      Returns the logger used by this filter.
      Specified by:
      getLogger in class FilterBase
      Returns:
      the logger instance

    • selectEncoding

      protected String selectEncoding(ServletRequest request)
      Select an appropriate character encoding to be used, based on the characteristics of the current request and/or filter initialization parameters. If no character encoding should be set, return null.

      The default implementation unconditionally returns the value configured by the encoding initialization parameter for this filter.

      Parameters:
      request - The servlet request we are processing
      Returns:
      the encoding that was configured