javaEE-03-cookie与session

最新推荐文章于 2025-05-30 20:16:38 发布

阿胡爱编程

最新推荐文章于 2025-05-30 20:16:38 发布

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文章标签： java-ee java

本文链接：https://blog.youkuaiyun.com/m0_72926194/article/details/140694231

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文章目录

Cookie
Session 会话

Cookie

Cookie 是服务器通知客户端保存键值对的一种技术,客户端有了 Cookie 后，每次请求都发送给服务器并且每个 Cookie 的大小不能超过 4kb。

创建Cookie

创建一个新的servlet程序CookieServlet

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class CookieServlet extends HttpServlet {
   

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
   
    	resp.setContentType("text/html;charset=utf-8");
        //1 创建Cookie 对象
        Cookie cookie = new Cookie("username", "root");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie);
        //1 创建Cookie 对象
        Cookie cookie1 = new Cookie("password", "123456");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie1);
        resp.getWriter().write("Cookie 创建成功");
    }

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

增加新的映射文件web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
	<servlet>
        <servlet-name>CookieServlet</servlet-name>
        <servlet-class>CookieServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name