JavaWeb中如何使用filter清空網頁緩存

package cm.xls.czq;


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.HttpServletResponse;




public class TestFilter implements Filter {


@Override
public void destroy() {
System.out.println("銷燬前 Filter............");
}


@Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {


      // response對象  
               HttpServletResponse res = (HttpServletResponse) response;  
          
       // 設定網頁的到期時間，一旦過期則必須到服務器上重新調用  
      res.setDateHeader("Expires", -1);  
         
        //Cache-Control 指定請求和響應應遵循的緩存機制 no-cache指示請求或響應消息是不能緩存的  
      res.setHeader("Cache-Control", "no-cache");  
         
      // 用於設定禁止瀏覽器從本地緩存中調用頁面內容，設定後一旦離開頁面就無法從Cache中再調出  
      res.setHeader("Pragma", "no-cache");  
         
       // 放行  
       chain.doFilter(request, res);
}


@Override
public void init(FilterConfig arg0) throws ServletException {

System.out.println("初始化Filter............");

}


}