package rabbit.filter;import java.nio.channels.SocketChannel;import rabbit.http.HttpHeader;import rabbit.proxy.Connection;import rabbit.util.Logger;import rabbit.util.SProperties;/** A filter for http headers.  */public interface HttpFilter {    /** test if a socket/header combination is valid or      *  return a new HttpHeader.     * @param socket the Socket that made the request.     * @param header the actual request made.     * @param con the Connection handling the request.     * @return null if everything is fine or a HTTPHeader      *         describing the error (like a 403).     */    HttpHeader doHttpInFiltering (SocketChannel socket, 				  HttpHeader header, 				  Connection con);        /** test if a socket/header combination is valid or      *  return a new HttpHeader.     * @param socket the Socket that made the request.     * @param header the actual request made.     * @param con the Connection handling the request.     * @return null if everything is fine or a HTTPHeader      *         describing the error (like a 403).     */    HttpHeader doHttpOutFiltering (SocketChannel socket, 				   HttpHeader header, 				   Connection con);    /** Setup this filter.     * @param logger the Logger to output errors/warnings on.     * @param properties the SProperties to get the settings from.     */    void setup (Logger logger, SProperties properties);}