[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。