Cookie会话技术——快速入门

目录

Cookie：

 1.概念：客户端会话数据技术，将数据保存到客户端。

  2.快速入门：

3.实现原理：

---

 

Cookie：

 1.概念：客户端会话数据技术，将数据保存到客户端。

 

  2.快速入门：

 使用步骤:

        ①创建Cookie对象，绑定数据

        new Cookie(String name,String value)

        ②发送Cookie对象

        response.addCookie(Cookie cookie)

        ③获取Cookie，拿到数据

        Cookie[] request.getCookies()

 

CookieDemo1类：

package jason.lh.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;


//Cookie快速入门

@WebServlet("/CookieDemo1")
public class CookieDemo1 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

         //①创建Cookie对象
        Cookie c = new Cookie("msg","Hello");
        //②发送Cookie
        response.addCookie(c);
        //

    }

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

CookieDemo2类：

package jason.lh.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;


//Cookie快速入门

@WebServlet("/CookieDemo2")
public class CookieDemo2 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //③获取Cookie
        Cookie[] cs = request.getCookies();
        //④获取数据，遍历Cookies
        if (cs != null) {
            for (Cookie c : cs) {
                String name = c.getName();
                String value = c.getValue();
                System.out.println(name + ":" + value);
            }

        }
    }

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

}

虚拟目录位/day16

控制台输出：

 

3.实现原理：

基于响应set-cookie和请求头cookie实现