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01-Cookie&Session1

2023-08-18 68
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简介： 01-Cookie&Session1

创建新模块13_cookie_session并且add web,然后创建Tomcat实例13_cookie_session

1、Cookie 饼干

视频

a) 什么是Cookie?

1.Cookie翻译过来是饼干的意思。

2、Cooke是服务器通知客户端保存键值对的一种技术

3、客户端有了Cookie后，每次请求都发送给服务器。

4、每个Cookie的大小不能超过4kb

准备

web下cookie.html

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.O1 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="pragma" content="no-cache" />
<meta http-equiv="cache-control" kontent="no-cache" />
<meta http-equiv="Expires" content="0" />
<meta http-equiv="content-Type" content="text/html; charset=UTF-8">
<title>Cookie</title>
    <style type="text/css">
        ul li{
            list-style:none;
        }
    </style>
</head>
<body>
<iframe name="target" width="500"  height="500" style="..."></iframe>
    <div style="...">
        <ul>
            <li><a href="" target="target">Cookie的创建</a></li>
            <li><a href="" target="target">cookie的获取</a></li>
            <li><a href="" target="target">cookie值的修改</a></li>
            <li>cookie的存活周期</li>
            <li>
                <ul>
                    <li><a href="" target="target">cookie的默认存活时间(会话)</a></li>
                    <li><a href="" target="target">Cookie立即删除</a></li>
                    <li><a href="" target="target">Cookie存活3600秒(1小时)</a></li>
                </ul>
            </li>
            <li><a href="" target="target">Cookie的路径设置</a></li>
            <li><a href="" target="target">Cookie的用户免登录练习</a></li>
        </ul>
    </div>
</body>
</html>

导入 service.jar包

src/ 新建 com.servlet包/ 复制 BaseServlet

package com.servlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Method;
public abstract class BaseServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req,resp);
    }
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String action=req.getParameter("action");
        //action的value和调用的方法名是统一的
        //反射
        try {
            //获取action业务鉴别字符串，获取相应的业务方法 反射对象
            Method method = this.getClass().getDeclaredMethod(action,HttpServletRequest.class,HttpServletResponse.class);
            //调用目标业务方法
            method.invoke(this,req,resp);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

b)如何创建Cookie



新建CookieServlet servlet包下,并配置web.xml

package com.servlet;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class CookieServlet extends BaseServlet{
    protected void createCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1 创建Cookie对象
        Cookie cookie =new Cookie("key1","value1");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie);
         //1 创建Cookie对象
        Cookie cookie2 = new Cookie("key2", "value2");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie2);
        //1 创建Cookie对象
        Cookie cookie3 = new Cookie("key3", "value3");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie3);
        resp.getWriter().write("Cookie创建成功");
    }
}

修改 cookie.html

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.O1 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="pragma" content="no-cache" />
<meta http-equiv="cache-control" kontent="no-cache" />
<meta http-equiv="Expires" content="0" />
<meta http-equiv="content-Type" content="text/html; charset=UTF-8">
<title>Cookie</title>
    <base href="http://localhost:8080/13_cookie_session/">
    <style type="text/css">
        ul li{
            list-style:none;
        }
    </style>
</head>
<body>
<iframe name="target" width="500"  height="500" style="..."></iframe>
    <div style="...">
        <ul>
            <li><a href="cookieServlet?action=createCookie" target="target">Cookie的创建</a></li>
            <li><a href="" target="target">cookie的获取</a></li>
            <li><a href="" target="target">cookie值的修改</a></li>
            <li>cookie的存活周期</li>
            <li>
                <ul>
                    <li><a href="" target="target">cookie的默认存活时间(会话)</a></li>
                    <li><a href="" target="target">Cookie立即删除</a></li>
                    <li><a href="" target="target">Cookie存活3600秒(1小时)</a></li>
                </ul>
            </li>
            <li><a href="" target="target">Cookie的路径设置</a></li>
            <li><a href="" target="target">Cookie的用户免登录练习</a></li>
        </ul>
    </div>
</body>
</html>

修改 BaseServlet 以解决中文乱码

package com.servlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Method;
public abstract class BaseServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req,resp);
    }
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //解决post请求中文乱码问题
        //一定要在获取请求参数之前调用才有效
        req.setCharacterEncoding("UTF-8");
        //解决响应中文乱码问题
        resp.setContentType("text/html;charset=UTF-8");
        String action=req.getParameter("action");
        //action的value和调用的方法名是统一的
        //反射
        try {
            //获取action业务鉴别字符串，获取相应的业务方法 反射对象
            Method method = this.getClass().getDeclaredMethod(action,HttpServletRequest.class,HttpServletResponse.class);
            //调用目标业务方法
            method.invoke(this,req,resp);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

结果


c) 服务器如何获取coolie


服务器获取客户端的Cookie只需一行代码：req.getCookies() : Cookie[]

修改 cookie.html

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.O1 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="pragma" content="no-cache" />
<meta http-equiv="cache-control" kontent="no-cache" />
<meta http-equiv="Expires" content="0" />
<meta http-equiv="content-Type" content="text/html; charset=UTF-8">
<title>Cookie</title>
    <base href="http://localhost:8080/13_cookie_session/">
    <style type="text/css">
        ul li{
            list-style:none;
        }
    </style>
</head>
<body>
<iframe name="target" width="500"  height="500" style="..."></iframe>
    <div style="...">
        <ul>
            <li><a href="cookieServlet?action=createCookie" target="target">Cookie的创建</a></li>
            <li><a href="cookieServlet?action=getCookie" target="target">cookie的获取</a></li>
            <li><a href="" target="target">cookie值的修改</a></li>
            <li>cookie的存活周期</li>
            <li>
                <ul>
                    <li><a href="" target="target">cookie的默认存活时间(会话)</a></li>
                    <li><a href="" target="target">Cookie立即删除</a></li>
                    <li><a href="" target="target">Cookie存活3600秒(1小时)</a></li>
                </ul>
            </li>
            <li><a href="" target="target">Cookie的路径设置</a></li>
            <li><a href="" target="target">Cookie的用户免登录练习</a></li>
        </ul>
    </div>
</body>
</html>

增加语句 CookieServlet

package com.servlet;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class CookieServlet extends BaseServlet {
    protected void createCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1 创建Cookie对象
        Cookie cookie = new Cookie("key1", "value1");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie);
        //1 创建Cookie对象
        Cookie cookie2 = new Cookie("key2", "value2");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie2);
        //1 创建Cookie对象
        Cookie cookie3 = new Cookie("key3", "value3");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie3);
        resp.getWriter().write("Cookie创建成功");
    }
    protected void getCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Cookie[] cookies = req.getCookies();
        for (Cookie cookie : cookies) {
            //getName  方法返回Cookie的key（名）
            //getValue 方法返回Cookie的value（值）
            resp.getWriter().write("Cookie["+cookie.getName()+"="+cookie.getValue()+"]<br>");
        }
    }
}

结果



获取指定的Cookie

修改 CookieServlet

package com.servlet;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class CookieServlet extends BaseServlet {
    protected void createCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1 创建Cookie对象
        Cookie cookie = new Cookie("key1", "value1");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie);
        //1 创建Cookie对象
        Cookie cookie2 = new Cookie("key2", "value2");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie2);
        //1 创建Cookie对象
        Cookie cookie3 = new Cookie("key3", "value3");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie3);
        resp.getWriter().write("Cookie创建成功");
    }
    protected void getCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Cookie[] cookies = req.getCookies();
        for (Cookie cookie : cookies) {
            //getName  方法返回Cookie的key（名）
            //getValue 方法返回Cookie的value（值）
            resp.getWriter().write("Cookie["+cookie.getName()+"="+cookie.getValue()+"]<br>");
        }
        Cookie iWantCookie =null;
        for (Cookie cookie : cookies) {
            if ("key2".equals(cookie.getName())){
                iWantCookie=cookie;
                break;
            }
        }
        //如果不等于null，说明赋过值，也就是找到了需要的Cookie
        if (iWantCookie!=null){
            resp.getWriter().write("找到了需要的Cookie");
        }
    }
}

结果


创建工具类以获取指定的Cookie

com/创建util包/创建CookieUtils类

package com.util;
import javax.servlet.http.Cookie;
public class CookieUtils {
    /**
     * 查找指定名称的Cookie对象
     * @param name
     * @param cookies
     * @return
     */
    public static Cookie findCookie(String name,Cookie[] cookies){
        if (name==null||cookies==null||cookies.length==0){
            return null;
        }
        for (Cookie cookie : cookies) {
            if (name.equals(cookie.getName())){
                return cookie;
            }
        }
        return null;
    }
}

修改 CookieServlet

package com.servlet;
import com.util.CookieUtils;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class CookieServlet extends BaseServlet {
    protected void createCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1 创建Cookie对象
        Cookie cookie = new Cookie("key1", "value1");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie);
        //1 创建Cookie对象
        Cookie cookie2 = new Cookie("key2", "value2");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie2);
        //1 创建Cookie对象
        Cookie cookie3 = new Cookie("key3", "value3");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie3);
        resp.getWriter().write("Cookie创建成功");
    }
    protected void getCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Cookie[] cookies = req.getCookies();
        for (Cookie cookie : cookies) {
            //getName  方法返回Cookie的key（名）
            //getValue 方法返回Cookie的value（值）
            resp.getWriter().write("Cookie["+cookie.getName()+"="+cookie.getValue()+"]<br>");
        }
        Cookie iWantCookie = CookieUtils.findCookie("key1",cookies);
//        for (Cookie cookie : cookies) {
//            if ("key2".equals(cookie.getName())){
//                iWantCookie=cookie;
//                break;
//            }
//        }
        //如果不等于null，说明赋过值，也就是找到了需要的Cookie
        if (iWantCookie!=null){
            resp.getWriter().write("找到了需要的Cookie");
        }
    }
}


d) Cookie值的修改

方案一

1、先创建一个要修改的同名的Cookie对象

2、在构造器，同时赋于新的Cookie值。

3、调用response.addCookie( Cookie );

修改 cookie.html

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.O1 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="pragma" content="no-cache" />
<meta http-equiv="cache-control" kontent="no-cache" />
<meta http-equiv="Expires" content="0" />
<meta http-equiv="content-Type" content="text/html; charset=UTF-8">
<title>Cookie</title>
    <base href="http://localhost:8080/13_cookie_session/">
    <style type="text/css">
        ul li{
            list-style:none;
        }
    </style>
</head>
<body>
<iframe name="target" width="500"  height="500" style="..."></iframe>
    <div style="...">
        <ul>
            <li><a href="cookieServlet?action=createCookie" target="target">Cookie的创建</a></li>
            <li><a href="cookieServlet?action=getCookie" target="target">cookie的获取</a></li>
            <li><a href="cookieServlet?action=updateCookie" target="target">cookie值的修改</a></li>
            <li>cookie的存活周期</li>
            <li>
                <ul>
                    <li><a href="" target="target">cookie的默认存活时间(会话)</a></li>
                    <li><a href="" target="target">Cookie立即删除</a></li>
                    <li><a href="" target="target">Cookie存活3600秒(1小时)</a></li>
                </ul>
            </li>
            <li><a href="" target="target">Cookie的路径设置</a></li>
            <li><a href="" target="target">Cookie的用户免登录练习</a></li>
        </ul>
    </div>
</body>
</html>

增加语句 CookieServlet

package com.servlet;
import com.util.CookieUtils;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class CookieServlet extends BaseServlet {
    protected void createCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1 创建Cookie对象
        Cookie cookie = new Cookie("key1", "value1");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie);
        //1 创建Cookie对象
        Cookie cookie2 = new Cookie("key2", "value2");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie2);
        //1 创建Cookie对象
        Cookie cookie3 = new Cookie("key3", "value3");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie3);
        resp.getWriter().write("Cookie创建成功");
    }
    protected void getCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Cookie[] cookies = req.getCookies();
        for (Cookie cookie : cookies) {
            //getName  方法返回Cookie的key（名）
            //getValue 方法返回Cookie的value（值）
            resp.getWriter().write("Cookie["+cookie.getName()+"="+cookie.getValue()+"]<br>");
        }
        Cookie iWantCookie = CookieUtils.findCookie("key1",cookies);
//        for (Cookie cookie : cookies) {
//            if ("key2".equals(cookie.getName())){
//                iWantCookie=cookie;
//                break;
//            }
//        }
        //如果不等于null，说明赋过值，也就是找到了需要的Cookie
        if (iWantCookie!=null){
            resp.getWriter().write("找到了需要的Cookie");
        }
    }
    protected void updateCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//        方案一
//        1、先创建一个要修改的同名的Cookie对象
//        2、在构造器，同时赋于新的Cookie值。
        Cookie cookie=new Cookie("key1","newValue1");
//        3、调用response.addCookie( Cookie );//通知客户端保存修改
        resp.addCookie(cookie);
        resp.getWriter().write("key1的Cookie已经修改好");
    }
}

结果

方案二:

1、先查找到需要修改的Cookie对象

2、调用setValue()方法赋于新的Cookie值。

3、调用response.addCookie()通知客户端保存修改

修改 CookieServlet

package com.servlet;
import com.util.CookieUtils;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class CookieServlet extends BaseServlet {
    protected void createCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1 创建Cookie对象
        Cookie cookie = new Cookie("key1", "value1");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie);
        //1 创建Cookie对象
        Cookie cookie2 = new Cookie("key2", "value2");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie2);
        //1 创建Cookie对象
        Cookie cookie3 = new Cookie("key3", "value3");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie3);
        resp.getWriter().write("Cookie创建成功");
    }
    protected void getCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Cookie[] cookies = req.getCookies();
        for (Cookie cookie : cookies) {
            //getName  方法返回Cookie的key（名）
            //getValue 方法返回Cookie的value（值）
            resp.getWriter().write("Cookie["+cookie.getName()+"="+cookie.getValue()+"]<br>");
        }
        Cookie iWantCookie = CookieUtils.findCookie("key1",cookies);
//        for (Cookie cookie : cookies) {
//            if ("key2".equals(cookie.getName())){
//                iWantCookie=cookie;
//                break;
//            }
//        }
        //如果不等于null，说明赋过值，也就是找到了需要的Cookie
        if (iWantCookie!=null){
            resp.getWriter().write("找到了需要的Cookie");
        }
    }
    protected void updateCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        方案一
        1、先创建一个要修改的同名的Cookie对象
        2、在构造器，同时赋于新的Cookie值。
//        Cookie cookie=new Cookie("key1","newValue1");
        3、调用response.addCookie( Cookie );//通知客户端保存修改
//        resp.addCookie(cookie);
//        resp.getWriter().write("key1的Cookie已经修改好");
//        方案二:
//        1、先查找到需要修改的Cookie对象
        Cookie cookie=CookieUtils.findCookie("key2",req.getCookies());
        if (cookie!=null){
//        2、调用setValue()方法赋于新的Cookie值。
        cookie.setValue("newValue2");
//        3、调用response.addCookie()通知客户端保存修改
            resp.addCookie(cookie);
        }
        resp.getWriter().write("key2的Cookie已经修改好");
    }
}

结果

注意



e) 浏览器查看Cookie

谷歌浏览器如何查看Cookie



火狐浏览器如何查看Cookie



f)Cookie 生命控制

Cookie的生命控制指的是如何管理cookie什么时候被销毁〈删除)

setMaxAge()

正数，表示在指定的秒数后过期

负数，表示浏览器一关，Cookie就会被删除（默认值是-1）

零，表示马上删除Cookie

修改 cookie.html

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.O1 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="pragma" content="no-cache" />
<meta http-equiv="cache-control" kontent="no-cache" />
<meta http-equiv="Expires" content="0" />
<meta http-equiv="content-Type" content="text/html; charset=UTF-8">
<title>Cookie</title>
    <base href="http://localhost:8080/13_cookie_session/">
    <style type="text/css">
        ul li{
            list-style:none;
        }
    </style>
</head>
<body>
<iframe name="target" width="500"  height="500" style="..."></iframe>
    <div style="...">
        <ul>
            <li><a href="cookieServlet?action=createCookie" target="target">Cookie的创建</a></li>
            <li><a href="cookieServlet?action=getCookie" target="target">cookie的获取</a></li>
            <li><a href="cookieServlet?action=updateCookie" target="target">cookie值的修改</a></li>
            <li>cookie的存活周期</li>
            <li>
                <ul>
                    <li><a href="cookieServlet?action=defaultLife" target="target">cookie的默认存活时间(会话)</a></li>
                    <li><a href="cookieServlet?action=deleteNow" target="target">Cookie立即删除</a></li>
                    <li><a href="cookieServlet?action=life3600" target="target">Cookie存活3600秒(1小时)</a></li>
                </ul>
            </li>
            <li><a href="" target="target">Cookie的路径设置</a></li>
            <li><a href="" target="target">Cookie的用户免登录练习</a></li>
        </ul>
    </div>
</body>
</html>

修改 CookieServlet

package com.servlet;
import com.util.CookieUtils;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class CookieServlet extends BaseServlet {
    protected void createCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1 创建Cookie对象
        Cookie cookie = new Cookie("key1", "value1");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie);
        //1 创建Cookie对象
        Cookie cookie2 = new Cookie("key2", "value2");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie2);
        //1 创建Cookie对象
        Cookie cookie3 = new Cookie("key3", "value3");
        //2 通知客户端保存Cookie
        resp.addCookie(cookie3);
        resp.getWriter().write("Cookie创建成功");
    }
    protected void getCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Cookie[] cookies = req.getCookies();
        for (Cookie cookie : cookies) {
            //getName  方法返回Cookie的key（名）
            //getValue 方法返回Cookie的value（值）
            resp.getWriter().write("Cookie["+cookie.getName()+"="+cookie.getValue()+"]<br>");
        }
        Cookie iWantCookie = CookieUtils.findCookie("key1",cookies);
//        for (Cookie cookie : cookies) {
//            if ("key2".equals(cookie.getName())){
//                iWantCookie=cookie;
//                break;
//            }
//        }
        //如果不等于null，说明赋过值，也就是找到了需要的Cookie
        if (iWantCookie!=null){
            resp.getWriter().write("找到了需要的Cookie");
        }
    }
    protected void updateCookie(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        方案一
        1、先创建一个要修改的同名的Cookie对象
        2、在构造器，同时赋于新的Cookie值。
//        Cookie cookie=new Cookie("key1","newValue1");
        3、调用response.addCookie( Cookie );//通知客户端保存修改
//        resp.addCookie(cookie);
//        resp.getWriter().write("key1的Cookie已经修改好");
//        方案二:
//        1、先查找到需要修改的Cookie对象
        Cookie cookie=CookieUtils.findCookie("key2",req.getCookies());
        if (cookie!=null){
//        2、调用setValue()方法赋于新的Cookie值。
        cookie.setValue("newValue2");
//        3、调用response.addCookie()通知客户端保存修改
            resp.addCookie(cookie);
        }
        resp.getWriter().write("key2的Cookie已经修改好");
    }
    protected void defaultLife(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Cookie cookie=new Cookie("defaultLife","defaultLife");
        cookie.setMaxAge(-1);//设置存活时间
        resp.addCookie(cookie);
    }
    protected void deleteNow(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //先找到你要删除的Cookie对象
        Cookie cookie=CookieUtils.findCookie("key3",req.getCookies());
        if (cookie!=null){
            //调用setMaxAge(0)
            cookie.setMaxAge(0);//表示马上删除，都不需要等待浏览器关闭
            //调用response.addCookie( Cookie )
            resp.addCookie(cookie);
            resp.getWriter().write("key3的Cookie已经被删除");
        }
    }
    protected void life3600(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //先找到你要删除的Cookie对象
        Cookie cookie=new Cookie("life3600","life3600");
        cookie.setMaxAge(60*60);//设置Cookie一小时之后被删除，无效
        resp.addCookie(cookie);
        resp.getWriter().write("已经创建了一个存活一小时的Cookie");
    }
}

结果






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