大家用过@WebServlet("/Demo")这种方式写Servlet吗？


我怎么感觉不稳定，有时候启动Tomcat7.0合适着呢，有时候不合适。是不是我写的有问题呢？
我请求 http://localhost:8080/TempWeb/Demo报404HTTP Status 404 - /TempWeb/Demo--------------------------------------------------------------------------------type Status reportmessage /TempWeb/Demodescription The requested resource (/TempWeb/Demo) is not available.package cn.liushaoxiong.www;import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;/**
 * Servlet implementation class Demo
 */
@WebServlet("/Demo")
public class Demo 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 {
System.out.println("Hello");
} /**
 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
 */
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("Hello");
}}