过滤器在Web开发应用------解决中文乱码

src/com/Encoding.java

package com;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class Encoding implements Filter{
    protected String encoding=null;
    protected FilterConfig config;
    @Override
    public void destroy() {
        // TODO Auto-generated method stub

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        // TODO Auto-generated method stub
        if(request.getCharacterEncoding()==null){
            String encode=getEncoding();
            if(encode!=null){
                request.setCharacterEncoding(encode);
                response.setCharacterEncoding(encode);
            }
        }
        chain.doFilter(request, response);
    }

    @Override
    public void init(FilterConfig config) throws ServletException {
        // TODO Auto-generated method stub
        this.config=config;
        this.encoding=config.getInitParameter("Encode");
    }

    protected String getEncoding(){
        return encoding;
    }

}

web.xml

<?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>

  <filter>
      <filter-name>EncodeFilter</filter-name>
      <filter-class>com.Encoding</filter-class>
      <init-param>
          <param-name>Encode</param-name>
          <param-value>GB2312</param-value>
      </init-param>
  </filter>

  <filter-mapping>
      <filter-name>EncodeFilter</filter-name>
      <url-pattern>/*</url-pattern>
  </filter-mapping>

</web-app>