java web 設置cookie
更改啟動端口
// 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
項目基本信息
- 項目類型 :Java Web應用
技術棧分析 - 后端 :Java Servlet
- 前端 :JSP、HTML
- 構建工具 :可能使用IntelliJ IDEA自帶構建系統
- 包含用戶登錄頁面(login.html)
- 可能實現ServletContext相關功能
- 包含Cookie處理模塊(src/com/zhang/ServletContext/cookie目錄)
訪問
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. 創建Cookie對象,綁定數據Cookie cookie = new Cookie("msg", "hello");cookie.setMaxAge(300);Cookie cookie1 = new Cookie("masg", "123");Cookie cookie2 = new Cookie("mmm", "張三");cookie2.getPath();cookie.setDomain("day21");// 2. 發送Cookie對象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. 獲取Cookie,拿到數據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 {//設置相應消息頭的格式和編碼方式response.setContentType("text/html;charset=utf-8");//1、獲取所有的cookieCookie[] cookies = request.getCookies();boolean flag = false;//false代表第一次訪問if (cookies != null || cookies.length > 0) {//2、遍歷cookiefor (Cookie cookie : cookies) {//3、獲取cookie的名字String name = cookie.getName();//4、判斷是否存在名為:lastTime的cookieif (name.equals("lastTime")) {//有該Cookie,不是第一次訪問flag = true;//true不是一次訪問//響應數據//獲取Cookie的value,時間String value = cookie.getValue();//解碼System.out.println("解碼前是:" + value);value = URLDecoder.decode(value, "utf-8");System.out.println("解碼后是:" + value);//獲取當前時間的字符串,重新設置Cookie的值,重新發送cookieDate date = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");String str_date = sdf.format(date);//URL編碼System.out.println("編碼前是:" + str_date);str_date = URLEncoder.encode(str_date, "utf-8");System.out.println("編碼后是:" + str_date);//設置cookie值 timecookie.setValue(str_date);//設置cookie的存活時間 --- 1個月cookie.setMaxAge(60 * 60 * 24 * 30);//把cookie寫回瀏覽器保存response.addCookie(cookie);response.getWriter().write("<h1>歡迎回來,您上次訪問的時間是:" + value + "</h1>");break;}}}if (cookies == null || cookies.length == 0 || flag == false) {//沒有名為lastTime的cookie,是第一次訪問//獲取當前時間的字符串,重新設置Cookie的值,重新發送cookieDate date = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");String str_date = sdf.format(date);//URL編碼System.out.println("編碼前是:" + str_date);str_date = URLEncoder.encode(str_date, "utf-8");System.out.println("編碼后是:" + str_date);//新建cookieCookie cookie = new Cookie("lastTime", str_date);//設置cookie的存活時間 --- 1個月cookie.setMaxAge(60 * 60 * 24 * 30);//把cookie寫回瀏覽器保存response.addCookie(cookie);//響應數據response.getWriter().write("<h1>您好,歡迎您首次訪問!</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 {//設置相應消息頭的格式和編碼方式response.setContentType("text/html;charset=utf-8");//1、獲取所有的cookieCookie[] cookies = request.getCookies();boolean flag = false;//false代表第一次訪問if (cookies != null || cookies.length > 0) {//2、遍歷cookiefor (Cookie cookie : cookies) {//3、獲取cookie的名字String name = cookie.getName();//4、判斷是否存在名為:lastTime的cookieif (name.equals("lastTime")) {//有該Cookie,不是第一次訪問flag = true;//true不是一次訪問//響應數據//獲取Cookie的value,時間String value = cookie.getValue();//解碼System.out.println("解碼前是:" + value);value = URLDecoder.decode(value, "utf-8");System.out.println("解碼后是:" + value);//獲取當前時間的字符串,重新設置Cookie的值,重新發送cookieDate date = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");String str_date = sdf.format(date);//URL編碼System.out.println("編碼前是:" + str_date);str_date = URLEncoder.encode(str_date, "utf-8");System.out.println("編碼后是:" + str_date);//設置cookie值 timecookie.setValue(str_date);//設置cookie的存活時間 --- 1個月cookie.setMaxAge(60 * 60 * 24 * 30);//把cookie寫回瀏覽器保存response.addCookie(cookie);response.getWriter().write("<h1>歡迎回來,您上次訪問的時間是:" + value + "</h1>");break;}}}if (cookies == null || cookies.length == 0 || flag == false) {//沒有名為lastTime的cookie,是第一次訪問//獲取當前時間的字符串,重新設置Cookie的值,重新發送cookieDate date = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");String str_date = sdf.format(date);//URL編碼System.out.println("編碼前是:" + str_date);str_date = URLEncoder.encode(str_date, "utf-8");System.out.println("編碼后是:" + str_date);//新建cookieCookie cookie = new Cookie("lastTime", str_date);//設置cookie的存活時間 --- 1個月cookie.setMaxAge(60 * 60 * 24 * 30);//把cookie寫回瀏覽器保存response.addCookie(cookie);//響應數據response.getWriter().write("<h1>您好,歡迎您首次訪問!</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目錄下資源訪問System.out.println(b);String c = context.getRealPath("/WEB-INF/c.txt");//WEB-INF目錄下的資源訪問System.out.println(c);String a = context.getRealPath("/WEB-INF/classes/a.txt");//src目錄下的資源訪問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案例改寫</title>
</head>
<body>
<%Cookie[] cookies = request.getCookies();boolean flag = false;//false代表第一次訪問if (cookies != null || cookies.length > 0) {//2、遍歷cookiefor (Cookie cookie : cookies) {//3、獲取cookie的名字String name = cookie.getName();//4、判斷是否存在名為:lastTime的cookieif (name.equals("lastTime")) {//有該Cookie,不是第一次訪問flag = true;//true不是一次訪問//響應數據//獲取Cookie的value,時間String value = cookie.getValue();//解碼System.out.println("解碼前是:" + value);value = URLDecoder.decode(value, "utf-8");System.out.println("解碼后是:" + value);//獲取當前時間的字符串,重新設置Cookie的值,重新發送cookieDate date = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");String str_date = sdf.format(date);//URL編碼System.out.println("編碼前是:" + str_date);str_date = URLEncoder.encode(str_date, "utf-8");System.out.println("編碼后是:" + str_date);//設置cookie值 timecookie.setValue(str_date);//設置cookie的存活時間 --- 1個月cookie.setMaxAge(60 * 60 * 24 * 30);//把cookie寫回瀏覽器保存response.addCookie(cookie);%>
<h1>歡迎回來,您上次訪問的時間是:<%=value%>
</h1>
<%break;}}}if (cookies == null || cookies.length == 0 || flag == false) {//沒有名為lastTime的cookie,是第一次訪問//獲取當前時間的字符串,重新設置Cookie的值,重新發送cookieDate date = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");String str_date = sdf.format(date);//URL編碼System.out.println("編碼前是:" + str_date);str_date = URLEncoder.encode(str_date, "utf-8");System.out.println("編碼后是:" + str_date);//新建cookieCookie cookie = new Cookie("lastTime", str_date);//設置cookie的存活時間 --- 1個月cookie.setMaxAge(60 * 60 * 24 * 30);//把cookie寫回瀏覽器保存response.addCookie(cookie);//響應數據
%>
<h1>您好,歡迎您首次訪問!</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">訪問</button>
</form></body>
</html>