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会话技术–Cookie–特点&作用

会话技术–Cookie–案例–分析

会话技术–Cookie–案例–实现

package cn.itcast.cookie; import javax.servlet.ServletException; import javax.servlet.ServletOutputStream; import javax.servlet.annotation.WebServlet; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.PrintWriter; import java.text.SimpleDateFormat; import java.util.Date; @WebServlet("/Cookie_Test1") public class Cookie_Test1 extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); PrintWriter writer = response.getWriter(); Cookie[] cookies = request.getCookies(); if(cookies!=null&&cookies.length!=0) { for (Cookie cookie : cookies) { if (cookie.getName().equals("msg")) { //writer.write("欢迎回来"); writer.write(cookie.getValue()); cookie.setValue("欢迎回来，" + new SimpleDateFormat("yyyy年MM月dd日HH:mm:ss").format(new Date())); response.addCookie(cookie); cookie.setMaxAge(60*60*24*30); return; } } } writer.write("您好，欢迎您首次访问"); Cookie msg = new Cookie("msg", "欢迎回来，" + new SimpleDateFormat("yyyy年MM月dd日HH:mm:ss").format(new Date())); response.addCookie(msg); msg.setMaxAge(60*60*24*30); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } }