1.自定义处理字符集类，实现Filter接口：CharFilter.java

1. package com.util;  
2.  
3. import java.io.IOException;  
4.  
5. import javax.servlet.Filter;  
6. import javax.servlet.FilterChain;  
7. import javax.servlet.FilterConfig;  
8. import javax.servlet.ServletException;  
9. import javax.servlet.ServletRequest;  
10. import javax.servlet.ServletResponse;  
11. import javax.servlet.http.HttpServletRequest;  
12.  
13. public class CharFilter implements Filter  
14. {  
15.     private String targetEncoding;  
16.     /**  
17.      *   
18.      * {还原到原始编码格式}  
19.      *   
20.      * @author:LJ  
21.      */ 
22.     public void destroy()  
23.     {  
24.         targetEncoding = null;  
25.     }  
26.     /**  
27.      *   
28.      * {对请求和响应字符集过滤}  
29.      *   
30.      * @param srequest  
31.      * @param sresponse  
32.      * @param chain  
33.      * @throws IOException  
34.      * @throws ServletException  
35.      * @author:LJ  
36.      */ 
37.     public void doFilter(ServletRequest srequest, ServletResponse sresponse, FilterChain chain) throws IOException,  
38.             ServletException  
39.     {  
40.         HttpServletRequest request = (HttpServletRequest) srequest;  
41.         request.setCharacterEncoding(targetEncoding);  
42.         sresponse.setContentType("text/html;charset=GBK");  
43.         chain.doFilter(srequest, sresponse); ///派发请求  
44.     }  
45.     /**  
46.      *   
47.      * {初始化字符集编码格式}  
48.      *   
49.      * @param config  
50.      * @throws ServletException  
51.      * @author:LJ  
52.      */ 
53.     public void init(FilterConfig config) throws ServletException  
54.     {  
55.         targetEncoding = config.getInitParameter("encoding");  
56.     }  
57. } 

2.web.xml配置：

1. <filter> 
2.      <filter-name>filter</filter-name>   
3.      <filter-class>com.util.CharFilter</filter-class>    
4.      <init-param> 
5.             <param-name>encoding</param-name> 
6.             <param-value>GBK</param-value> 
7.      </init-param>         
8. </filter>     
9. <filter-mapping>   
10.        <filter-name>filter</filter-name>   
11.        <url-pattern>/*</url-pattern>    
12. </filter-mapping>