package com.demo.test;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 characterEncodingFilter implements Filter {        private String characterEncoding;    private boolean enabled;    public void destroy() {        // TODO Auto-generated method stub        characterEncoding = null;//销毁时清空资源    }    public void doFilter(ServletRequest request, ServletResponse response,            FilterChain chain) throws IOException, ServletException {        // TODO Auto-generated method stub        if(enabled || characterEncoding != null){//如果启用该Filter            request.setCharacterEncoding(characterEncoding);//设置reques编码            response.setCharacterEncoding(characterEncoding);//设置response编码        }        chain.doFilter(request,response );//doFilter,执行下一个Filter或者Servlet    }    public void init(FilterConfig config) throws ServletException {//初始化时加载参数        // TODO Auto-generated method stub        characterEncoding = config.getInitParameter(characterEncoding);//编码方式        enabled = "true".equalsIgnoreCase(config.getInitParameter("enabled").trim());//启用    }  }

<?xml version="1.0" encoding="UTF-8"?><web-app version="2.5"     xmlns="http://java.sun.com/xml/ns/javaee"     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee     http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">  <display-name></display-name>      <welcome-file-list>    <welcome-file>index.jsp</welcome-file>  </welcome-file-list>  <filter>    <filter-name>characterEncodingFilter</filter-name>    <filter-class>com.helloweenvsfei.filter.CharacterEncodingFilter</filter-class>    <init-param>      <param-name>characterEncoding</param-name>      <param-value>UTF-8</param-value>    </init-param>    <init-param>      <param-name>enabled</param-name>      <param-value>true</param-value>    </init-param>  </filter>  <filter-mapping>    <filter-name>characterEncodingFilter</filter-name>    <url-pattern>/*</url-pattern>  </filter-mapping></web-app>