用filter解决汉字编码及禁止页面缓存

用filter解决汉字编码及禁止页面缓存
package beanservlettest;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;

public class servfilter extends HttpServlet implements Filter {
private FilterConfig filterConfig;
//Handle the passed-in FilterConfig
public void init(FilterConfig filterConfig) {
this.filterConfig = filterConfig;
}
//Process the request/response pair
public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) {
try {
request.setCharacterEncoding("GB2312");//设置编码
((HttpServletResponse)response).setHeader("Pragma","No-cache");
((HttpServletResponse)response).setHeader("Cache-Control","no-cache");
((HttpServletResponse)response).setHeader("Expires","0");//禁止缓存
filterChain.doFilter(request, response);
}
catch(ServletException sx) {
filterConfig.getServletContext().log(sx.getMessage());
}
catch(IOException iox) {
filterConfig.getServletContext().log(iox.getMessage());
}
}
//Clean up resources
public void destroy() {
}
}

下面是在web.xml里的配置：
# <filter>
# <filter-name>servfilter</filter-name>
# <filter-class>beanservlettest.servfilter</filter-class>
# </filter>
# <filter-mapping>
# <filter-name>servfilter</filter-name>
# <url-pattern>/*</url-pattern>

# </filter-mapping>