[转]Java Web乱码过滤器

本文转自http://blog.csdn.net/l271640625/article/details/6388690

大家都知道，在jsp里乱码是最让人讨厌的东西，有些乱码出来的莫名其妙，给开发带来很大困扰，但搞一个乱码过滤器就一切都解决了，配置好之后，你并不需要在页面里进行转码之类的。

        首先，写一个过滤器类，如下：

 package filter;  

 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;
 import javax.servlet.http.HttpServletRequest;  

 public class PageEncodingFilter implements Filter{  

     private String encoding = "UTF-8";
     protected FilterConfig filterConfig;  

     public void init(FilterConfig filterConfig) throws ServletException {
         this.filterConfig = filterConfig;
         //本过滤器默认编码是UTF-8，但也可以在web.xml配置文件里设置自己需要的编码
         if(filterConfig.getInitParameter("encoding") != null)
             encoding = filterConfig.getInitParameter("encoding");
     }  

     public void doFilter(ServletRequest srequset, ServletResponse sresponse,
             FilterChain filterChain) throws IOException, ServletException {
         HttpServletRequest request = (HttpServletRequest)srequset;
         request.setCharacterEncoding(encoding);
         filterChain.doFilter(srequset, sresponse);
     }  

     public void destroy() {
         this.encoding = null;
     }  

 }  

然后，在web.xml里配置，如下：

 <filter>
         <filter-name>Encoding</filter-name>
         <filter-class>filter.PageEncodingFilter</filter-class>
         <init-param>
             <param-name>encoding</param-name>
             <param-value>UTF-8</param-value>
         </init-param>
     </filter>  

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

到这里，一切就OK了，你可以放心的写代码了，而不会担心出现乱码了。