1 package com.xiaostudy.servlet;
 2 
 3 import java.io.IOException;
 4 import java.io.PrintWriter;
 5 
 6 import javax.servlet.ServletException;
 7 import javax.servlet.annotation.WebServlet;
 8 import javax.servlet.http.Cookie;
 9 import javax.servlet.http.HttpServlet;
10 import javax.servlet.http.HttpServletRequest;
11 import javax.servlet.http.HttpServletResponse;
12 
13 @WebServlet("/Cookie_1")
14 public class Cookie_1 extends HttpServlet {
15     private static final long serialVersionUID = 1L;
16 
17     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
18         PrintWriter out = response.getWriter();
19         response.setContentType("text/html;charset=UTF-8");
20         
21         out.print("<a href=" + request.getContextPath() + "/Cookie_2?book=java>java</a><br/>");
22         out.print("<a href=" + request.getContextPath() + "/Cookie_2?book=python>python</a><br/>");
23         out.print("<a href=" + request.getContextPath() + "/Cookie_2?book=c#>c#</a><br/>");
24         out.print("<a href=" + request.getContextPath() + "/Cookie_2?book=php>php</a><br/>");
25         out.print("<hr/>");
26         Cookie[] cookies = request.getCookies();//获取cookie集合
27         for(int i=0; cookies!=null && i<cookies.length; i++) {//循环cookie集合
28             if("book".equals(cookies[i].getName())) {//判断cookie是否有自己存放的name和value
29                 String[] books = cookies[i].getValue().split("-");//拿到所有的点击value集合
30                 for(int j=0; j<books.length; j++) {//循环输出显示
31                     out.print(books[j] + "<br/>");
32                 }
33             }
34         }
35         
36     }
37 
38     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
39         doGet(request, response);
40     }
41 
42 }

 1 package com.xiaostudy.servlet;
 2 
 3 import java.io.IOException;
 4 import java.io.PrintWriter;
 5 
 6 import javax.servlet.ServletException;
 7 import javax.servlet.annotation.WebServlet;
 8 import javax.servlet.http.Cookie;
 9 import javax.servlet.http.HttpServlet;
10 import javax.servlet.http.HttpServletRequest;
11 import javax.servlet.http.HttpServletResponse;
12 
13 @WebServlet("/Cookie_2")
14 public class Cookie_2 extends HttpServlet {
15     private static final long serialVersionUID = 1L;
16        
17     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
18         response.setContentType("text/html;charset=UTF-8");
19         PrintWriter out = response.getWriter();
20         String book = (String)request.getParameter("book");
21         String str = book;
22         Cookie[] cookies = request.getCookies();//得到cookie的集合数组
23         for(int i=0; cookies!=null && i<cookies.length; i++) {//循环cookie
24             if("book".equals(cookies[i].getName())) {//看看以前有没有放过
25                 String[] books = cookies[i].getValue().split("-");//做切割
26                 for(int j=0; j<books.length; j++) {//循环元素
27                     if(!book.equals(books[j])) {//排除已经点击过的
28                         str = str + "-" + books[j];
29                     }
30                 }
31             }
32         }
33         Cookie ck = new Cookie("book", str);//创建一个cookie，并且添加name和value
34         ck.setPath("/");//说明为当前的应用
35         ck.setMaxAge(5);//保存cookie的时间，单位为秒
36         response.addCookie(ck);//服务器向浏览器添加cookie
37         out.print("成功添加书籍：" + book + "<br/>2秒后返回主页。。。");//输出到浏览器的信息
38         
39         //响应消息头，2秒后跳转到指定页面
40         response.setHeader("refresh", "2;url=" + request.getContextPath() + "/Cookie_1");
41     }
42 
43     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
44         doGet(request, response);
45     }
46 
47 }