Servlet 3.1 读取 Cookie
Java Servlet 可以使用 HttpServletRequest 类的 getCookies( ) 获取 Cookies
getCookies( ) 方法会返回一个 javax.servlet.http.Cookie 对象的数组
然后遍历数组,使用使用 getName() 和 getValue() 方法就能得到每个 cookie 和关联的值
范例
下面的范例可以读取上一章节中设置的 Cookie
// author: 简单教程(www.twle.cn) // Copyright © 2015-2065 www.twle.cn. All rights reserved. package cn.twle.demo; import java.io.*; import java.util.*; import javax.servlet.*; import javax.servlet.http.*; import java.net.URLDecoder; import javax.servlet.annotation.WebServlet;; @WebServlet(name = "ReadCookiesServlet", urlPatterns = {"read_cookie"}, loadOnStartup = 1) public class ReadCookiesServlet extends HttpServlet { private static final long serialVersionUID = 1L; public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { Cookie cookie = null; Cookie[] cookies = null; // 获取与该域相关的 Cookie 的数组 cookies = request.getCookies(); // 设置响应内容类型 response.setContentType("text/html;charset=UTF-8"); PrintWriter out = response.getWriter(); String title = "读取 Cookie 范例| 简单教程(www.twle.cn)"; String docType = "<!DOCTYPE html>\n"; out.println(docType + "<title>" + title + "</title>" + "<body bgcolor=\"#f0f0f0\">\n" ); if( cookies != null ) { out.println("<h2>Cookie 名称和值</h2>"); for (int i = 0; i < cookies.length; i++){ cookie = cookies[i]; if((cookie.getName( )).compareTo("name") == 0 ){ cookie.setMaxAge(0); response.addCookie(cookie); out.print("已删除的 cookie:" + cookie.getName( ) + "<br/>"); } out.print("名称:" + cookie.getName( ) + ","); out.print("值:" + URLDecoder.decode(cookie.getValue(), "utf-8") +" <br/>"); } }else{ out.println( "<p style=\"color:red\">No Cookie founds</h2>"); } } }
在浏览器上输入 http://localhost:8080/servlet/read_cookie 显示结果如下