public class Servlet1 extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { System.out.println("get"); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { System.out.println("post"); doGet(request, response); }}控制台显示结果是什么
时间: 2024-04-27 09:25:39 浏览: 195
如果你在浏览器中使用 GET 请求方式访问 Servlet1,那么控制台将输出 "get"。如果你在浏览器中使用 POST 请求方式访问 Servlet1,那么控制台将输出 "post" 和 "get"。
这是因为在给定的代码中,doGet() 方法输出 "get",doPost() 方法输出 "post",并且在 doPost() 方法中调用了 doGet() 方法。因此,无论使用 GET 还是 POST 请求方式,都会调用 doGet() 方法并输出 "get"。如果使用 POST 请求方式,还会输出 "post"。
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请帮我解释以下代码:@WebServlet("/demo2") public class SessionDemo2 extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { HttpSession session = request.getSession(); System.out.println(session); Object username = session.getAttribute("username"); System.out.println(username); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doGet(request, response); } }
这段代码是一个使用Java Servlet技术实现的Servlet类,它的URL映射路径为"/demo2"。当客户端向服务器发送一个GET请求时,Servlet会调用doGet()方法来响应请求,当客户端向服务器发送一个POST请求时,Servlet会调用doPost()方法来响应请求。在这个Servlet中,doGet()方法中获取了一个HttpSession对象,并通过getAttribute()方法获取了这个Session中名为"username"的属性值,最后将其打印到控制台上。如果这个属性不存在,它将打印null。这段代码可以用于演示如何在Java Servlet中使用Session对象来存储和获取用户信息。
public class DownloadServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request,response); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String local = "/home/hadoop/Downloads"; String filePath = new String(request.getParameter("filePath").getBytes("ISO-8859-1"),"GB2312"); System.out.println(filePath); JobConf conf = HDFSDao.getConfig(); HDFSDao hdfs = new HDFSDao(conf); hdfs.download(filePath, local); FileStatus[] list = hdfs.ls("hdfs://master:9000/user/hadoop"); request.setAttribute("list", list); request.getRequestDispatcher("index.jsp").forward(request, response); } } System.out.println( "Download Successfully!" ); }
这是一个名为 DownloadServlet 的公共类,继承了 HttpServlet 类。它有一个 serialVersionUID 属性,并设置为 1L。该类实现了 HttpServlet 类的方法。
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