Class 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 Detail

      • SetCharacterEncodingFilter

        public SetCharacterEncodingFilter()
    • Method Detail

      • setEncoding

        public void setEncoding​(String encoding)
      • getEncoding

        public String getEncoding()
      • setIgnore

        public void setIgnore​(boolean ignore)
      • isIgnore

        public boolean isIgnore()
      • 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
      • 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