设置浏览器缓存

当web资源长期保持不变时，可以用来提高效率

package cn.itcast.web.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

//设置浏览器的缓存
public class ServletDemo14 extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        long expriestime = System.currentTimeMillis() + 1*24*60*60*1000;
        response.setDateHeader("expires", expriestime);
        String data = "adsdfsdfsdfsdfdsf";
        response.getWriter().write(data);

    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }

}