做网站为职业生存不下去,网络推广渠道有哪些,兰州建设厅评职称网站,百胜招聘 网站开发文章目录 Cookie的详解使用#xff08;创建#xff0c;获取#xff0c;销毁#xff09;1、Cookie是什么2、cookie的常用方法3、cookie的构造和获取代码演示SetCookieServlet.javaGetCookieServlet.javaweb.xml运行结果如下 4、Cookie的销毁DestoryCookieServletweb.xml运行… 文章目录 Cookie的详解使用创建获取销毁1、Cookie是什么2、cookie的常用方法3、cookie的构造和获取代码演示SetCookieServlet.javaGetCookieServlet.javaweb.xml运行结果如下 4、Cookie的销毁DestoryCookieServletweb.xml运行结果如下,刚才设置的cookie已经没了 Cookie的详解使用创建获取销毁
1、Cookie是什么 cookie是在浏览器中保存的 如果想要使用cookie要保证我们的浏览器是开启cookie所以说有一定的弊端如果浏览器没有开启cookie就不能再使用cookie了 cookie的大小是有限制的通常是4096byte cookie的保存是以键值对的形式存在的 2、cookie的常用方法
//1.cookie的构造方法目的是实例化出来cookie对象
Cookie(String name,String value)
//2.设置cookie的方法
setValue(String value) //修改cookie的值
getValue(String value) //获得cookie的值
getName(String value) //获得cookie的键
setMaxAge(int time) //设置cookie的有效时间
//3.要将cookie发送到浏览器
response.addCookie(Cookie cookie);
//4.获得所有cookie
request.getCookies();3、cookie的构造和获取代码演示
SetCookieServlet.java
/** Copyright (c) 2020, 2023, fpl1116.cn All rights reserved.**/
package cn.fpl.servlet;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;/*** pProject: JavaWebDemo - SetCookieServlet/p* pPowered by fpl1116 On 2023-12-27 09:50:33/p* p描述p** author fpl1116 [2391940642qq.com]* version 1.0* since 1.8*/
public class SetCookieServlet extends HttpServlet {Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {doPost(req, resp);}Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//创建cookie对象Cookie cookie new Cookie(fpl,fpl1116);//设置过期时间cookie.setMaxAge(60*60*24);//发送浏览器响应resp.addCookie(cookie);}
}
GetCookieServlet.java
/** Copyright (c) 2020, 2023, fpl1116.cn All rights reserved.**/
package cn.fpl.servlet;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;
import java.util.ArrayList;/*** pProject: JavaWebDemo - SetCookieServlet/p* pPowered by fpl1116 On 2023-12-27 09:50:33/p* p描述p** author fpl1116 [2391940642qq.com]* version 1.0* since 1.8*/
public class GetCookieServlet extends HttpServlet {Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {doPost(req, resp);}Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {Cookie[] cookies req.getCookies();for(Cookie cookie : cookies){System.out.println();System.out.println(cookie.getName());System.out.println(cookie.getValue());}}
}
web.xml
servletservlet-namesetcookie/servlet-nameservlet-classcn.fpl.servlet.SetCookieServlet/servlet-class/servletservlet-mappingservlet-namesetcookie/servlet-nameurl-pattern/setcookie/url-pattern/servlet-mappingservletservlet-namegetcookie/servlet-nameservlet-classcn.fpl.servlet.GetCookieServlet/servlet-class/servletservlet-mappingservlet-namegetcookie/servlet-nameurl-pattern/getcookie/url-pattern/servlet-mapping运行结果如下
setcookie
getcookie 4、Cookie的销毁
DestoryCookieServlet
package cn.fpl.servlet;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 DestoryCookieServlet extends HttpServlet {Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {doPost(req, resp);}Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//获得所有cookieCookie[] cookieArr req.getCookies();for (Cookie cookie : cookieArr) {if(fpl.equals(cookie.getName())){//修改fpl的失效时间cookie.setMaxAge(0);resp.addCookie(cookie);}}}
}
web.xml
servletservlet-namedestoryCookie/servlet-nameservlet-classcn.fpl.servlet.DestoryCookieServlet/servlet-class/servletservlet-mappingservlet-namedestoryCookie/servlet-nameurl-pattern/destoryCookie/url-pattern/servlet-mapping运行结果如下,刚才设置的cookie已经没了
