Cookie使用示例：获取上次访问时间示例,和记住用户名和密码的示例

Cookie：获取上次访问时间的servlet

package com.web.servlet; import java.io.IOException; import java.text.SimpleDateFormat; import java.util.Date; 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; /** * Cookie：获取上次访问时间 * @title CookieServlet.java */ @WebServlet("/cookie") public class CookieServlet extends HttpServlet { private static final long serialVersionUID = -5633460440471261682L; @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-ddHH:mm:ss"); // 1、获取Cookie对象 Cookie[] cookies = request.getCookies(); if (cookies != null) { for (Cookie cookie : cookies) { // 2、获取Cookie的名称 String name = cookie.getName(); // 3、判断是否是指定的cookie if ("mydate".equals(name)) { String value = cookie.getValue(); System.out.println("上次访问时间为：" + value); response.getWriter().print(value); // 把新的时间写出 cookie.setValue(sdf.format(new Date())); response.addCookie(cookie); } } } else { // 注意：Cookie的值不能有空格 Cookie cookie = new Cookie("mydate", sdf.format(new Date())); cookie.setMaxAge(60*60); // 1分钟 response.addCookie(cookie); } } }

记住用户名和密码的servlet

package com.web.servlet; import java.io.IOException; 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; /** * 记住用户名 * @title LoginServlet.java */ @WebServlet("/login") public class LoginServlet extends HttpServlet { private static final long serialVersionUID = -7217213344249352985L; @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 设置编码 request.setCharacterEncoding("utf-8"); // 接收参数 String name = request.getParameter("name"); String password = request.getParameter("password"); String rememberme = request.getParameter("rememberme"); // 判断是否勾选记住用户名 if (rememberme != null) { // 如果勾选，则添加cookie Cookie cookie = new Cookie("hpeu", name); cookie.setMaxAge(60*60*5); // 5分钟 response.addCookie(cookie); } else { // 如果没有勾选，则删除cookie Cookie[] cookies = request.getCookies(); if (cookies != null) { for (Cookie cookie : cookies) { String cn = cookie.getName(); if ("hpeu".equals(cn)) { cookie.setMaxAge(0); // 删除cookie response.addCookie(cookie); } } } } System.out.println(name); System.out.println(password); System.out.println(rememberme); } }