Filters not working with Tomcat 5

Question

Hi,
I've attempted to implement a filter in my JSP program. Below is the web.xml I'm using and the filter implementation.
The problem is doFilter simply isn't being called. init is called because when I do an ant reload it print my error into the log but doPost never prints anything anywhere. Please help!!! I'm completely foxed.
I thought it might be something to do with the FilterConfig as I don't understand how its set or called but as I don't understand, I don't know?
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>
    <description>themoves.co.uk Content Management System</description>
    <display-name>themoves.co.uk CMS</display-name>
    <filter>
         <filter-name>authFilter</filter-name>
         <filter-class>uk.co.themoves.AuthenticationFilter</filter-class>
    </filter>
    <filter-mapper>
         <filter-name>authFilter</filter-name>
         <url-pattern>/Controller</url-pattern>
    </filter-mapper>
    <servlet>
        <servlet-name>Controller</servlet-name>
        <servlet-class>uk.co.themoves.Controller</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>Controller</servlet-name>
        <url-pattern>/Controller</url-pattern>
    </servlet-mapping>   
    <session-config>
        <session-timeout>15</session-timeout>
    </session-config>
    <welcome-file-list>
        <welcome-file>/WEB-INF/welcome.jsp</welcome-file>
    </welcome-file-list>
    <taglib>
      <taglib-uri>http://java.sun.com/jstl/fmt</taglib-uri>
      <taglib-location>/WEB-INF/fmt.tld</taglib-location>
    </taglib>
    <taglib>
      <taglib-uri>http://java.sun.com/jstl/fmt-rt</taglib-uri>
      <taglib-location>/WEB-INF/fmt-rt.tld</taglib-location>
    </taglib>
    <taglib>
      <taglib-uri>http://java.sun.com/jstl/core</taglib-uri>
      <taglib-location>/WEB-INF/c.tld</taglib-location>
    </taglib>
    <taglib>
      <taglib-uri>http://java.sun.com/jstl/core-rt</taglib-uri>
      <taglib-location>/WEB-INF/c-rt.tld</taglib-location>
    </taglib>
    <taglib>
      <taglib-uri>http://java.sun.com/jstl/sql</taglib-uri>
      <taglib-location>/WEB-INF/sql.tld</taglib-location>
    </taglib>
    <taglib>
      <taglib-uri>http://java.sun.com/jstl/sql-rt</taglib-uri>
      <taglib-location>/WEB-INF/sql-rt.tld</taglib-location>
    </taglib>
    <taglib>
      <taglib-uri>http://java.sun.com/jstl/x</taglib-uri>
      <taglib-location>/WEB-INF/x.tld</taglib-location>
    </taglib>
    <taglib>
      <taglib-uri>http://java.sun.com/jstl/x-rt</taglib-uri>
      <taglib-location>/WEB-INF/x-rt.tld</taglib-location>
    </taglib>
</web-app>Filter implementation
package uk.co.themoves;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
import java.io.IOException;
public class AuthenticationFilter implements Filter{
     private static final String LOGIN_PAGE = "/login.jsp";
     private FilterConfig config = null;
     private Connection db = null;
     public void init(FilterConfig _config) throws ServletException{
          System.err.println("init successful");
          this.config = _config;
          //do a database connection here
          if(db == null){
               try{
                    Class.forName("org.gjt.mm.mysql.Driver");
                    this.db = DriverManager.getConnection("jdbc:mysql://localhost:3306/themoves", "cwaig", "UUyGiRPE");
               } catch (Exception e){
                    System.out.println("error Connecting to themoves DB: " + e.toString());
     public void doFilter(ServletRequest _req, ServletResponse _res, FilterChain _chain) throws IOException, ServletException{
          System.err.println("doFilter");
          //cast the Servlet to a httpServlet
          HttpServletRequest httpReq = (HttpServletRequest) _req;
          HttpSession session = httpReq.getSession();
          String uid = httpReq.getParameter("uid");
          String password = httpReq.getParameter("pass");
          //if action is login then login else check
          String action = (String) httpReq.getParameter("action");
          if(action.equals("login")){
               //check the username and password
               UserManager userManager = new UserManager(this.db, uid, password);
               if(userManager.auth()){
                    //set session variable and carry on
                    session.setAttribute("uid", uid);
                    _chain.doFilter(_req, _res);
               } else {
                    //go back to the login page
                    RequestDispatcher rd = httpReq.getRequestDispatcher(LOGIN_PAGE);
                    rd.forward(_req, _res);
          } else {
               //check the session to make sure they are logged in
               String session_uid = (String) session.getAttribute("uid");
               if(session_uid == null){
                    RequestDispatcher rd = httpReq.getRequestDispatcher(LOGIN_PAGE);
                    rd.forward(_req, _res);     
               } else {
                    //set session variable and carry on
                    session.setAttribute("uid", uid);
                    _chain.doFilter(_req, _res);
     public void destroy(){
          this.config = null;
          //clean up the database connection here
}

Answer 1

First of all this is not correct:
<filter-mapper>
         <filter-name>authFilter</filter-name>
         <url-pattern>/Controller</url-pattern>
</filter-mapper>It is:
<filter-mapping>
         <filter-name>authFilter</filter-name>
         <url-pattern>/Controller</url-pattern>
</filter-mapping>
Also note that with this mapping configured onlt Servlets/JSPs called using the URL <your_domain>/<your_context>/Controller will be called.
Any other urls will not be subject to the filter.
I don't know all there is to know about filters, but I would be concerned that maybe your connection object is not thread safe being defined in the scope that it is.