java web 设置cookie
更改启动端口
// Directory tree (5 levels)
├── src\
│ ├── a.txt
│ └── com\
│ └── zhang\
│ └── ServletContext\
│ ├── cookie\
│ └── servletContext.java
└── web\├── WEB-INF\│ ├── c.txt│ └── javax.servlet.jar├── b.txt├── index.jsp└── login.html
项目基本信息
- 项目类型 :Java Web应用
技术栈分析 - 后端 :Java Servlet
- 前端 :JSP、HTML
- 构建工具 :可能使用IntelliJ IDEA自带构建系统
- 包含用户登录页面(login.html)
- 可能实现ServletContext相关功能
- 包含Cookie处理模块(src/com/zhang/ServletContext/cookie目录)
访问
http://localhost:8081/cookieDome1
http://localhost:8081/cookieDome2
http://localhost:8081/cookieTest
http://localhost:8081/cookieTest2
http://localhost:8081/servletContext
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 java.io.IOException;@WebServlet("/cookieDome1")
public class CookieDome1 extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// 1. 创建Cookie对象,绑定数据Cookie cookie = new Cookie("msg", "hello");cookie.setMaxAge(300);Cookie cookie1 = new Cookie("masg", "123");Cookie cookie2 = new Cookie("mmm", "张三");cookie2.getPath();cookie.setDomain("day21");// 2. 发送Cookie对象response.addCookie(cookie);response.addCookie(cookie1);response.addCookie(cookie2);}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request,response);}
}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 java.io.IOException;@WebServlet("/cookieDome2")
public class CookieDome2 extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// 3. 获取Cookie,拿到数据Cookie[] cookies = request.getCookies();
if(null!=cookies){for (Cookie cookie : cookies) {String name = cookie.getName();String value = cookie.getValue();System.out.println(name + ":" + value);}}}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request,response);}
}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 java.io.IOException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.text.SimpleDateFormat;
import java.util.Date;@WebServlet("/cookieTest")
public class CookieTest extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//设置相应消息头的格式和编码方式response.setContentType("text/html;charset=utf-8");//1、获取所有的cookieCookie[] cookies = request.getCookies();boolean flag = false;//false代表第一次访问if (cookies != null || cookies.length > 0) {//2、遍历cookiefor (Cookie cookie : cookies) {//3、获取cookie的名字String name = cookie.getName();//4、判断是否存在名为:lastTime的cookieif (name.equals("lastTime")) {//有该Cookie,不是第一次访问flag = true;//true不是一次访问//响应数据//获取Cookie的value,时间String value = cookie.getValue();//解码System.out.println("解码前是:" + value);value = URLDecoder.decode(value, "utf-8");System.out.println("解码后是:" + value);//获取当前时间的字符串,重新设置Cookie的值,重新发送cookieDate date = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");String str_date = sdf.format(date);//URL编码System.out.println("编码前是:" + str_date);str_date = URLEncoder.encode(str_date, "utf-8");System.out.println("编码后是:" + str_date);//设置cookie值 timecookie.setValue(str_date);//设置cookie的存活时间 --- 1个月cookie.setMaxAge(60 * 60 * 24 * 30);//把cookie写回浏览器保存response.addCookie(cookie);response.getWriter().write("<h1>欢迎回来,您上次访问的时间是:" + value + "</h1>");break;}}}if (cookies == null || cookies.length == 0 || flag == false) {//没有名为lastTime的cookie,是第一次访问//获取当前时间的字符串,重新设置Cookie的值,重新发送cookieDate date = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");String str_date = sdf.format(date);//URL编码System.out.println("编码前是:" + str_date);str_date = URLEncoder.encode(str_date, "utf-8");System.out.println("编码后是:" + str_date);//新建cookieCookie cookie = new Cookie("lastTime", str_date);//设置cookie的存活时间 --- 1个月cookie.setMaxAge(60 * 60 * 24 * 30);//把cookie写回浏览器保存response.addCookie(cookie);//响应数据response.getWriter().write("<h1>您好,欢迎您首次访问!</h1>");}}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request, response);
}
}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 java.io.IOException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.text.SimpleDateFormat;
import java.util.Date;@WebServlet("/cookieTest2")
public class CookieTest2 extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//设置相应消息头的格式和编码方式response.setContentType("text/html;charset=utf-8");//1、获取所有的cookieCookie[] cookies = request.getCookies();boolean flag = false;//false代表第一次访问if (cookies != null || cookies.length > 0) {//2、遍历cookiefor (Cookie cookie : cookies) {//3、获取cookie的名字String name = cookie.getName();//4、判断是否存在名为:lastTime的cookieif (name.equals("lastTime")) {//有该Cookie,不是第一次访问flag = true;//true不是一次访问//响应数据//获取Cookie的value,时间String value = cookie.getValue();//解码System.out.println("解码前是:" + value);value = URLDecoder.decode(value, "utf-8");System.out.println("解码后是:" + value);//获取当前时间的字符串,重新设置Cookie的值,重新发送cookieDate date = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");String str_date = sdf.format(date);//URL编码System.out.println("编码前是:" + str_date);str_date = URLEncoder.encode(str_date, "utf-8");System.out.println("编码后是:" + str_date);//设置cookie值 timecookie.setValue(str_date);//设置cookie的存活时间 --- 1个月cookie.setMaxAge(60 * 60 * 24 * 30);//把cookie写回浏览器保存response.addCookie(cookie);response.getWriter().write("<h1>欢迎回来,您上次访问的时间是:" + value + "</h1>");break;}}}if (cookies == null || cookies.length == 0 || flag == false) {//没有名为lastTime的cookie,是第一次访问//获取当前时间的字符串,重新设置Cookie的值,重新发送cookieDate date = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");String str_date = sdf.format(date);//URL编码System.out.println("编码前是:" + str_date);str_date = URLEncoder.encode(str_date, "utf-8");System.out.println("编码后是:" + str_date);//新建cookieCookie cookie = new Cookie("lastTime", str_date);//设置cookie的存活时间 --- 1个月cookie.setMaxAge(60 * 60 * 24 * 30);//把cookie写回浏览器保存response.addCookie(cookie);//响应数据response.getWriter().write("<h1>您好,欢迎您首次访问!</h1>");}}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request, response);}
}import javax.servlet.ServletContext;
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 java.io.IOException;@WebServlet("/servletContext")
public class servletContext extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//this.ServletContext();ServletContext context = this.getServletContext();String b = context.getRealPath("/b.txt");//web目录下资源访问System.out.println(b);String c = context.getRealPath("/WEB-INF/c.txt");//WEB-INF目录下的资源访问System.out.println(c);String a = context.getRealPath("/WEB-INF/classes/a.txt");//src目录下的资源访问System.out.println(a);}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doPost(request,response);}
}
前端
<%@ page import="java.net.URLDecoder" %>
<%@ page import="java.util.Date" %>
<%@ page import="java.text.SimpleDateFormat" %>
<%@ page import="java.net.URLEncoder" %><%--Created by IntelliJ IDEA.User: 86133Date: 2020/10/25Time: 10:15To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head><title>cookie案例改写</title>
</head>
<body>
<%Cookie[] cookies = request.getCookies();boolean flag = false;//false代表第一次访问if (cookies != null || cookies.length > 0) {//2、遍历cookiefor (Cookie cookie : cookies) {//3、获取cookie的名字String name = cookie.getName();//4、判断是否存在名为:lastTime的cookieif (name.equals("lastTime")) {//有该Cookie,不是第一次访问flag = true;//true不是一次访问//响应数据//获取Cookie的value,时间String value = cookie.getValue();//解码System.out.println("解码前是:" + value);value = URLDecoder.decode(value, "utf-8");System.out.println("解码后是:" + value);//获取当前时间的字符串,重新设置Cookie的值,重新发送cookieDate date = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");String str_date = sdf.format(date);//URL编码System.out.println("编码前是:" + str_date);str_date = URLEncoder.encode(str_date, "utf-8");System.out.println("编码后是:" + str_date);//设置cookie值 timecookie.setValue(str_date);//设置cookie的存活时间 --- 1个月cookie.setMaxAge(60 * 60 * 24 * 30);//把cookie写回浏览器保存response.addCookie(cookie);%>
<h1>欢迎回来,您上次访问的时间是:<%=value%>
</h1>
<%break;}}}if (cookies == null || cookies.length == 0 || flag == false) {//没有名为lastTime的cookie,是第一次访问//获取当前时间的字符串,重新设置Cookie的值,重新发送cookieDate date = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");String str_date = sdf.format(date);//URL编码System.out.println("编码前是:" + str_date);str_date = URLEncoder.encode(str_date, "utf-8");System.out.println("编码后是:" + str_date);//新建cookieCookie cookie = new Cookie("lastTime", str_date);//设置cookie的存活时间 --- 1个月cookie.setMaxAge(60 * 60 * 24 * 30);//把cookie写回浏览器保存response.addCookie(cookie);//响应数据
%>
<h1>您好,欢迎您首次访问!</h1>
<%}
%></body>
</html><!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title>
</head>
<body>
<form action="/servletContext" method="post"><button type="submit">访问</button>
</form></body>
</html>