web开发中的中文乱码问题

1.写一个过滤器：
package com.cissst.utils;
import java.io.IOException;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
/**
*
*
*/
public class EncodingFilter implements Filter{
private String targetEncoding ;
protected FilterConfig filterConfig=null;
/**由Web容器调用，初始化此Filter*/
public void init(FilterConfig config) throws ServletException {
this.filterConfig=config;
this.targetEncoding=config.getInitParameter("encoding");
}
/**过滤处理方法*/
public void doFilter(ServletRequest request, ServletResponse response, FilterChain

chain) throws IOException,
ServletException {
/**对请求进行编码设置*/
HttpServletRequest srequest = (HttpServletRequest)request;
srequest.setCharacterEncoding(targetEncoding);
/**将处理权转交给下一个处理器*/
chain.doFilter(request, response);
}
/**由Web容器调用，销毁此Filter*/
public void destroy() {
this.targetEncoding=null;
this.filterConfig=null;
}
public void setFilterConfig(final FilterConfig filterConfig){
this.filterConfig=filterConfig;
}

}

2.在web.xml进行如下配置：

<!--  中文编码过滤器配置:主要是用来解决中文乱码问题 -->
<filter>
<filter-name>encodingFilter</filter-name>
<filter-class>com.cissst.utils.EncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>GBK</param-value>
</init-param>
<init-param>
<param-name>ignore</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>