用于处理指定编码请求的过滤器

import javax.servlet.*;
import java.io.IOException;

/**
 * 用于设置 HTTP 请求字符编码的过滤器，通过过滤器参数encoding指明使用何种字符编码,用于处理Html Form请求参数的中文问题
 */
public class CharacterEncodingFilter
 implements Filter
{
 protected FilterConfig filterConfig = null;
 protected String encoding = "";

 public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException
 {
        if(encoding != null)
         servletRequest.setCharacterEncoding(encoding);
  filterChain.doFilter(servletRequest, servletResponse);
 }

 public void destroy()
 {
  filterConfig = null;
  encoding = null;
 }

    public void init(FilterConfig filterConfig) throws ServletException
 {
  this.filterConfig = filterConfig;
        this.encoding = filterConfig.getInitParameter("encoding");

 }
}