response小结（四）

   1.发送http头，控制浏览器定时刷新网页（REFRESH）。

package com.yyz.response;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//定时刷新
public class ResponseDemo extends HttpServlet {

   public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setHeader("refresh", "5");
        response.setContentType("text/html;charset=UTF-8");
        response.setCharacterEncoding("UTF-8");
        response.getWriter().write("我是一个中国人！");
}
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
           doGet(request,response);
    }
}

   2.发送http头，控制浏览器禁止缓存当前文档的内容，通过下面三个消息头均可，但不同的浏览器支持不同的设置方式，所以开发中一般三句都写:

     response.setHeader("Expires", "-1");
     response.setHeader("Cache-Control", "no-cache");
     response.setHeader("Pragma", "no-cache");