有关于过滤器（Filter）的问题？？？

Question

问题可能有两种
1.你的URL映射写错了
2.你的过滤器写的有问题完整例子
import javax.servlet.http.*;
import java.io.*;
import java.util.*;public class SimpleFilter extends HttpServlet implements Filter {
    private FilterConfig filterConfig;
    //Handle the passed-in FilterConfig
    public void init(FilterConfig filterConfig) throws ServletException {
        this.filterConfig = filterConfig;
    }    //Process the request/response pair
    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain filterChain) {
        try {
            if (filterConfig == null) {
                throw new ServletException(
                        "FilterConfig not set before first request");
            }
            filterConfig.getServletContext().log("in SimpleFilter");
            System.out.println("in SimpleFilter");
            filterChain.doFilter(request, response);//重要
            filterConfig.getServletContext().log("Getting out of SimpleFilter");
            System.out.println("Getting out of SimpleFilter");
        } catch (ServletException sx) {
            filterConfig.getServletContext().log(sx.getMessage());
        } catch (IOException iox) {
            filterConfig.getServletContext().log(iox.getMessage());
        }
    }    //Clean up resources
    public void destroy() {
    }
}
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4">
  <filter>
    <filter-name>simplefilter</filter-name>
    <filter-class>myfilter.SimpleFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>simplefilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
  <filter>
    <filter-name>simplefilter2</filter-name>
    <filter-class>myfilter.SimpleFilter2</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>simplefilter2</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
</web-app>