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：

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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