会话-cookie

package com.hopetesting.cookie;

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;

/**
 * @author newcityman
 * @date 2019/9/2 - 21:35
 */
@WebServlet("/cookieDemo01")
public class CookieDemo04 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1、创建cookie对象
        Cookie c1 = new Cookie("msg", "hellocookie");
        //2、设置cookie的存活时间
        c1.setMaxAge(30);//持久化到硬盘，30秒后自动删除

        c1.setPath("/");  //设置跨项目访问cookie

//        c1.setMaxAge(-10);   //默认把数据存放到浏览器内存中，浏览器关闭后，cookie消失

//        c1.setMaxAge(0);   //删除cookie

        //3、发送cookie
        response.addCookie(c1);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

package com.hopetesting.cookie;

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;

/**
 * @author newcityman
 * @date 2019/9/2 - 21:36
 */
@WebServlet("/cookieDemo02")
public class CookieDemo02 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Cookie[] cookies = request.getCookies();
        if (cookies != null) {
            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 {
        this.doPost(request, response);
    }
}