1、必须继承HttpServlet类

package com.azhi.servlet;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class LoginServlet extends HttpServlet{    private static final long serialVersionUID = 1L;        @Override    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {        System.out.println("doGet");    }        @Override    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {        System.out.println("doPost");    }}

2、必须在web.xml上注册自定义的servlet

       
           
      
       loginServlet
            
      
       com.azhi.servlet.LoginServlet
        
       
       
           
      
       loginServlet
            
      
       /login