一、Cookie基本使用

1、发送Cookie

package com.itheima.web.cookie;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.net.URLEncoder;

@WebServlet("/aServlet")
public class AServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //发送Cookie

        //1. 创建Cookie对象
       Cookie cookie = new Cookie("username","zs");

        //2. 发送Cookie，response
        response.addCookie(cookie);
    }

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

2、获取Cookie

package com.itheima.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("/bServlet")
public class BServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //获取Cookie

        //1. 获取Cookie数组
        Cookie[] cookies = request.getCookies();

        //2. 遍历数组
        for (Cookie cookie : cookies) {
            //3. 获取数据
            String name = cookie.getName();
            if("username".equals(name)){
                String value = cookie.getValue();
                //URL解码
                value = URLDecoder.decode(value,"UTF-8");


                System.out.println(name+":"+value);

                break;
            }
        }

    }

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

二、Cookie原理

三、Cookie使用细节

package com.itheima.web.cookie;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.net.URLEncoder;

@WebServlet("/aServlet")
public class AServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //发送Cookie

        //1. 创建Cookie对象
//        Cookie cookie = new Cookie("username","zs");

        String value = "张三";
        //URL编码
        value = URLEncoder.encode(value, "UTF-8");
        System.out.println("存储数据："+value);

        Cookie cookie = new Cookie("username",value);

        //设置存活时间   ，1周 7天
        cookie.setMaxAge(60*60*24*7);

        //2. 发送Cookie，response
        response.addCookie(cookie);
    }

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