我做的servlet为什么什么也不输出

LoginTest的代码：

package demo;

import java.io.IOException;
import java.io.PrintWriter;

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 LoginTest
*/
@WebServlet("/LoginTest")
public class LoginTest extends HttpServlet {
private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */

/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}

/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
System.out.println("ds");

}

页面的代码：

<!DOCTYPE html>

MyHtml.html

   用户名：

   密&nbsp&nbsp&nbsp&nbsp码：

进入了登录页面点击登陆没反应，一开始听说servlet3.0以后可以不需要web.xml文件，但是我无法跳转也无法输出任何东西，这是怎么回事，后来又加了wen.xml文件并配置了参数，还是不行，请教一下怎么回事？

servlet3.0以后可以不需要web.xml文件?可以不要在web.xml里配置，直接用注解就可以了，但是web.xml还是要保留，