1.web.xml片段：

　　

     
       
      
       zhima_demo
        
          
       
        index.html
           
       
        index.htm
           
       
        index.jsp
           
       
        default.html
           
       
        default.htm
           
       
        default.jsp
         
        
          
       
        CharactorFilter
           
       
        filter.CharactorFilter
           
             
        
         encoding
              
        
         utf-8
            
         
        
          
       
        CharactorFilter
           
       
        /*
         
      
     

 2.实现类片段

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;public class CharactorFilter implements Filter { //继承Filter类    //字符编码    private String encoding = null;    public void doFilter(ServletRequest request, ServletResponse response,            FilterChain chain) throws IOException, ServletException {        if(encoding!=null){        //设置request字符编码            request.setCharacterEncoding(encoding);         //设置response字符编码            response.setContentType("text/html;charset="+encoding);        }        //传递给下一个过滤器        chain.doFilter(request, response);    }    public void init(FilterConfig filterConfig) throws ServletException {      //获取初始化参数        encoding=filterConfig.getInitParameter("encoding");    }    public void destroy() {        // TODO Auto-generated method stub        encoding=null;    }}