字符串编码过滤器

 package org.wlc.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;
import javax.servlet.http.HttpServletResponse;

public class CharacterFilter implements Filter {

	private String req;
	private String res;

	public void destroy() {
		// TODO Auto-generated method stub

	}

	
	public void doFilter(ServletRequest arg0, ServletResponse arg1,
			FilterChain arg2) throws IOException, ServletException {
		// TODO Auto-generated method stub

		HttpServletRequest request = (HttpServletRequest) arg0;
		HttpServletResponse response = (HttpServletResponse) arg1;
		request.setCharacterEncoding(req);
		response.setCharacterEncoding(res);
		arg2.doFilter(arg0, arg1);

	}

	
	public void init(FilterConfig config) throws ServletException {
		// TODO Auto-generated method stub

		req = config.getInitParameter("request");
		res = config.getInitParameter("response");
	}

}

xml
  

  <filter>
        <filter-name>MyFilter<filter-name>
        <filter-class>org.wlc.filter.CharacterFilter<filter-class>
      <init-param>
 	<param-name>request</param-name>
 	<param-value>UTF-8</param-value>
      </init-param>
      <init-param>
 	<param-name>response</param-name>
 	<param-value>UTF-8</param-value>
      </init-param>
    </filter>
     
      <filter-mapping>
        <filter-name>MyFilter<filter-name>
        <url-pattern>*<url-pattern>
      <filter-mapping>