package cn.soldier.session;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;/* * 模拟购物车页面页面 * */@WebServlet("/sessionDemo1")public class SessionDemo1 extends HttpServlet {    private static final long serialVersionUID = 1L;    protected void doGet(HttpServletRequest request,            HttpServletResponse response) throws ServletException, IOException {        response.setContentType("text/html;charset=utf-8");        PrintWriter out = response.getWriter();        HttpSession session = request.getSession();        session.setAttribute("buy", "电视机");        /*         * encodeUrl         *          * 为url构造JSESESSIONID，防止用户禁用cookie后，session失效。         * 第一次访问时encodeUrl会构造JSESESSIONID，         *  当判断到用户浏览器没有禁用cookie会关闭构造JSESESSIONID         */        String url1 = response.encodeUrl("ServletDemo/sessionDemo1");        String url2 = response.encodeUrl("ServletDemo/sessionDemo2");        out.write("<a href=http://www.mamicode.com/‘" + url1 + "‘>购买</a></br><a href=http://www.mamicode.com/‘" + url2                + "‘>结账</a>");        // 使session失效        /* session.invalidate(); */    }    protected void doPost(HttpServletRequest request,            HttpServletResponse response) throws ServletException, IOException {        doGet(request, response);    }}

package cn.soldier.session;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;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 javax.servlet.http.HttpSession;/** * 模拟结账页面 */@WebServlet("/sessionDemo2")public class SessionDemo2 extends HttpServlet {    private static final long serialVersionUID = 1L;    protected void doGet(HttpServletRequest request,            HttpServletResponse response) throws ServletException, IOException {        response.setContentType("text/html;charset=utf-8");        PrintWriter out = response.getWriter();        HttpSession session = request.getSession();        String sessionId = session.getId();        //设置cookie 是为了防止浏览器关闭用户丢失Session。        Cookie cookie = new Cookie("JSESESSIONID",sessionId);        cookie.setPath("day07");        cookie.setMaxAge(60*30);        response.addCookie(cookie);                String product = (String) session.getAttribute("buy");        out.write("您购买了" + product+"<br />");                String url1 =response.encodeUrl("ServletDemo/sessionDemo1");        String url2 =response.encodeUrl("ServletDemo/sessionDemo2");                out.write("<a href=http://www.mamicode.com/‘"+url1+"‘>购买</a></br><a href=http://www.mamicode.com/‘"+url2+"‘>结账</a>");    }    protected void doPost(HttpServletRequest request,            HttpServletResponse response) throws ServletException, IOException {    }}