cookie的创建、发送与接收--会话(页码CK1)

古城微笑少年丶 2023-07-17 14:22 9阅读 0赞

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cookie默认是会话级别的，如何延长cookie的持续时间呢  
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![在这里插入图片描述][20200322160049957.png]  
**发送cookie**

package cn.aynortechnology.cookie;
    
    import java.io.IOException;
    import javax.servlet.ServletException;
    import javax.servlet.http.Cookie;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    public class SendCookieServlet extends HttpServlet {
    
    	public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		//1.创建cookie对象
    		Cookie cookie = new Cookie("name","wangwang");
    		//2.设置Cookie再和护短的持久化时间，如果不设置持久化时间，cookie会存储在浏览器的内存中，浏览器关闭cookie存储的信息销毁，也就是会话级别的cookie
    		cookie.setMaxAge(60*10);//十分钟	---时间设置成0代表删除该cookie
    		//3.为Cookie设置携带的路径，如果不设置携带路径，那么该cookie会在与他同级的资源路径中携带信息
    		//cookie.setPath("/WEB16/sendCookie");//当访问sendCookie资源时才携带这个cookie
    		cookie.setPath("/WEB16");//当访问WEB16下的资源时都携带这个cookie
    		//cookie.setPath("/");//当访问服务器下所有的资源都携带这个cookie
    		//.将cookie中存储的信息发送到客户端----头
    		response.addCookie(cookie);
    	}
    
    	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		doGet(request, response);
    	}
    }

**接受cookie**

package cn.aynortechnology.cookie;
    
    import java.io.IOException;
    import javax.servlet.ServletException;
    import javax.servlet.http.Cookie;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    public class GetCookieServlet extends HttpServlet {
    
    	public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		//获得客户端携带的cookie数据
    		Cookie[] cookies = request.getCookies();
    		//通过cookie的名称获得想要的cookie
    		for(Cookie cookie : cookies) {
    			//获得cookie的名称
    			String cookieName = cookie.getName();
    			if(cookieName.equals("name")) {
    				//获得该cookie的值
    				String cookieValue = cookie.getValue();
    				System.out.println(cookieValue);
    			}
    		}
    	}
    
    	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		doGet(request, response);
    	}
    }

**删除cookie**

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package cn.aynortechnology.lastaccesstime;
    
    import java.io.IOException;
    import java.text.SimpleDateFormat;
    import java.util.Date;
    
    import javax.servlet.ServletException;
    import javax.servlet.http.Cookie;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    public class LastAccessTime extends HttpServlet {
    
    	public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		
    		//获得当前时间
    		Date date = new Date();
    		SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
    		String currentTime = format.format(date);
    		
    		//1.创建一个Cookie记录当前的最新访问时间
    		Cookie cookie = new Cookie("lastAccessTime", currentTime);
    		cookie.setMaxAge(60*10*500);
    		response.addCookie(cookie);
    		//2.获得客户端携带的cookie --- lastAccessTime
    		String lastAccessTime = null;
    		Cookie[] cookies = request.getCookies();
    		if(cookies!=null) {
    			for(Cookie coo : cookies) {
    				if(coo.getName().equals("lastAccessTime")) {
    					lastAccessTime = coo.getValue();
    				}
    			}
    		}
    		
    		response.setContentType("text/html;charset=UTF-8");
    		if(lastAccessTime==null) {
    			response.getWriter().write("您是第一次访问");
    		}else {
    			response.getWriter().write("您上次访问的时间是："+lastAccessTime);
    		}
    	}
    
    	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		doGet(request, response);
    	}
    }

[(页码CK1)cookie的创建、发送与接收–会话][CK1_cookie]  
[(页码CK2)session技术、完成验证码的校验–会话][CK2_session]

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[20200322160049957.png]: /images/20230528/b3600ad441244dc9b488e0769c840394.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwOTIyODQ1_size_16_color_FFFFFF_t_70 3]: /images/20230528/4b3bd62b9c3240119a57f79c58c0a07c.png
[CK1_cookie]: https://blog.csdn.net/qq_40922845/article/details/105029485
[CK2_session]: https://blog.csdn.net/qq_40922845/article/details/105033480