package com.atguigu.demo;import java.util.UUID;public class Demo { /** * * Cookie * 简介 * Cookie实际上就是服务器保存在浏览器上的一段信息，主要用于区分不同的用户。 * Cookie运行原理 * 请求 * 服务器创建一个Cookie对象，该Cookie对象携带用户信息，服务器发送（响应）给客户端 * 以后客户端再发送请求时，会携带该Cookie对象。 * 服务器会根据该Cookie对象（及信息），区分不同用户。 * Cookie * 创建 * Cookie cookie = new Cookie(String name,String value); * response.addCookie(cookie); * 获取 * Cookie[] cookies = request.getCookies(); * cookie.getName()|getValue() * 修改 * 覆盖式修改 * Cookie cookie = new Cookie("同名","新值"); * response.addCookie(cookie); * 直接修改 * Cookie[] cookies = request.getCookies(); * 找到指定的Cookie * cookie.setValue("新值"); * Cookie的键值问题 * name不可以为中文，value可以为中文，需要指定字符集问题，所有建议使用英文。 * Cookie有效性 * 默认为会话级别，与浏览器有关（关闭浏览器或换一个浏览器失效） * 持久化 * setMaxAge(ss:秒); * ss>0:在ss秒后失效 * ss=0:立即失效 * ss<0:默认会话级别 * 注意：持久化Cookie，该Cookie不是会话级别。 * Cookie有效路径 * 默认有效路径：当前项目路径 * setPath():一般设置有效路径，都是基于当前项目下的路径进行设置。 * 如：cookie.setPath(request.getContextPath()+"/a"); * Cookie应用 * 记住密码 * Cookie缺陷 * Cookie的value为String型，不灵活。 * Cookie存放在浏览器中，不安全。 * Cookie过多，会浪费流量。 * Session * 简介 * 类型：HttpSession * Session工作原理 * 请求 * 服务器创建Session,同时创建一个特殊的Cookie,该Cookie的key为固定值：JSESSIONID, value为session的id。 * 服务器将该Cookie对象发送（响应）给客户端 * 以后客户端再请求时，会携带该Cookie对象。 * 服务器会根据Cookie的value，找到相应的Session，从而区分不同的给用户。 * Session获取 * html(Servlet):request.getSession() * jsp:直接获取（session是jsp中的隐含对象） * Session有效性 * 默认有效性：当前会话（因为特殊的Cookie是会话级别） * 持久化Session * 持久化特殊Cookie * Session存活时间 * 默认存活时间为30分。 * 设置session的非活动时间 * web.xml中 30分钟 * session.setMaxInactiveInterval(ss秒); * ss>0:在ss秒后失效 * ss<=0:永不失效（Tomcat>=7） * session立即失效 * session.invalidate(); * Session钝化与活化 * 钝化：将session对象及session对象中的数据，一同从内存中序列化到硬盘的过程称之为钝化。 * 时机：服务器关闭时触发 * 活化：将session对象及session对象中的数据，一同从硬盘反序列化到内存的过程称之为活化。 * 时机：服务器重启时触发 * 表单重复提交问题 * 转发,F5 * 提交后，网速慢，连续点击提交按钮 * 提交后，点击回退按钮，继续提交 * 提交-Servlet-响应 * 思路：在Servlet中干预提交，第一次提交，以后不提交 1. 使用UUID，作为Token。将Token存放到session域和隐藏域中。 * UUID:是一个全球唯一的32为的16进制的随机数。 2. 提交，判断变量是否为初始值 true:提交，移除session域中的Token(UUID)。 false:不提交 */ public static void main(String[] args) { String uuid = UUID.randomUUID().toString().replace("-",""); System.out.println(uuid); } } package com.atguigu.servlet.cookie;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * Servlet implementation class CreateCookieServlet */public class CreateCookieServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //创建Cookie对象，并携带用户信息 Cookie cookieName = new Cookie("stuName", "zhangsan"); //响应给客户端 response.addCookie(cookieName); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); }} package com.atguigu.servlet.cookie;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * Servlet implementation class GetCookieServlet */public class GetCookieServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //获取Cookie Cookie[] cookies = request.getCookies(); for (Cookie cookie : cookies) { System.out.print("cookieName:"+cookie.getName()); System.out.println("cookieValue:"+cookie.getValue()); } } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); }} package com.atguigu.servlet.cookie;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * Servlet implementation class ChiCookieServlet */public class ChiCookieServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { Cookie cookie = new Cookie("stuAge", "18"); //持久化// cookie.setMaxAge(-1); //有效路径 cookie.setPath(request.getContextPath()+"/a"); response.addCookie(cookie); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); }} package com.atguigu.servlet.cookie;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * Servlet implementation class UserServlet */public class UserServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String username = request.getParameter("username"); String password = request.getParameter("password"); String rp = request.getParameter("rp"); if(rp != null) { //将数据存放Cookie中 Cookie cookieName = new Cookie("username", username); Cookie cookiePwd = new Cookie("cookiePwd", password); //将Cookie持久化 cookieName.setMaxAge(60); //7天=60*60*24*7 cookiePwd.setMaxAge(60); //将Cookie响应给浏览器 response.addCookie(cookieName); response.addCookie(cookiePwd); } //跳转 } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); }} <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>Insert title here CookieDemo
创建Cookie对象 获取Cookie对象 修改Cookie对象 持久化Cookie对象
package com.atguigu.servlet.session;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;/** * Servlet implementation class ShiSessionServlet */public class ShiSessionServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { HttpSession session = request.getSession(); //设置session失效 session.invalidate(); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); }} package com.atguigu.servlet.session;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;/** * Servlet implementation class GetSessionServlet */public class GetSessionServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { HttpSession session = request.getSession(); System.out.println(session.getId()); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); }} package com.atguigu.servlet.session;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;/** * Servlet implementation class ReSubServlet */public class ReSubServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { HttpSession session = request.getSession(); //分别取session域和隐藏域中的uuid值 String uuid2 = request.getParameter("uuid2"); Object uuid = session.getAttribute("uuid"); //判断是否相等， if(uuid != null && uuid.toString().equals(uuid2)) { //相等：提交，移除session域中的token System.out.println("提交啦！！！哈哈"); session.removeAttribute("uuid"); } System.out.println("end!"); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); }} package com.atguigu.servlet.session;import java.io.IOException;import javax.servlet.ServletException;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;import com.atguigu.bean.Student;/** * Servlet implementation class ChiSessionServlet */public class ChiSessionServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //持久化Session-》持久化特殊的Cookie Cookie[] cookies = request.getCookies(); for (Cookie cookie : cookies) { if("JSESSIONID".equals(cookie.getName())) { cookie.setMaxAge(600); response.addCookie(cookie); break; } } //设置session的非活动时间 HttpSession session = request.getSession(); session.setMaxInactiveInterval(600); session.setAttribute("stu", new Student("zhangsan")); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doGet(request, response); }} <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>Insert title here sessionId:<%=session.getId() %> 获取Session 持久化Session 设置Session立即失效 student:<%=session.getAttribute("stu") %>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>尚硅谷会员登录页面
<%@page import="java.util.UUID"%><%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>尚硅谷会员登录页面 <% String uuid = UUID.randomUUID().toString().replace("-", ""); session.setAttribute("uuid", uuid); %>