[Java知识库]Cookie和session的区别

文章目录

前言

一、Cookie

1.定义

2.Cookie的存活时间

3.Cookie存储中文

4.Cookie基本用法

package com.jkj.web.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;
import java.net.URLEncoder;

@WebServlet("/first")
public class FirstServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //创建cookie
        Cookie cookie = new Cookie("userName","jack");
        String value="小马哥";
        //url编码
        URLEncoder.encode(value,"utf-8");
        Cookie cookie1 = new Cookie("userName",value);
        //设置存活时间 60秒
        //cookie.setMaxAge(60);
        //发送cookie，response
        resp.addCookie(cookie);
        resp.addCookie(cookie1);
    }
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doGet(req, resp);
    }
}


package com.jkj.web.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;
import java.net.URLDecoder;

@WebServlet("/second")
public class SecondServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取cookie
        //获取cookie数组
        Cookie[] cookies = req.getCookies();
        //遍历数组
        for (Cookie cookie : cookies) {
            String name = cookie.getName();
            if ("userName".equals(name)){
                String value = cookie.getValue();
                //解码
                String values = URLDecoder.decode(value, "utf-8");
                //获取数据
                System.out.println(name+":"+values);
                //结束循环
                break;
            }
        }

    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doGet(req, resp);
    }
}

二、Session

1.Session活化

2.Session的使用

3.Session的销毁

4.Session实例

package com.jkj.web.session;

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 javax.servlet.http.HttpSession;
import java.io.IOException;
@WebServlet("/test1")
public class SessionTest1 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取session对象
        HttpSession session = req.getSession();
        //存储数据
        session.setAttribute("key1","jack");
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doGet(req, resp);
    }
}


package com.jkj.web.session;

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 javax.servlet.http.HttpSession;
import java.io.IOException;
@WebServlet("/test2")
public class SessionTest2 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取session对象
        HttpSession session = req.getSession();
        //接收数据
        Object value = session.getAttribute("key1");
        System.out.println(value);  //jack
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doGet(req, resp);
    }
}

三，Cookie和session的区别