字符编码过滤器

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");   
  
 }   
}

配置web.xml

<filter-name>CharacterEncodingFilter</filter-name>   
        <filter-class>CharacterEncodingFilter</filter-class>   
        <init-param>   
            <param-name>encoding</param-name>   
            <param-value>UTF-8</param-value>   
        </init-param>   
    </filter>   
    <filter-mapping>   
        <filter-name>CharacterEncodingFilter</filter-name>   
        <url-pattern>/*</url-pattern>   
    </filter-mapping>