JavaでWEBアプリケーションを作るのは複雑な作業です。しかし、私はベストを尽くします。

1.Javaをインストールする
2.IDE（EclipseまたはNetbeans）をインストールする。
3.OracleやMysqlなどのデータベース・マネージャーをインストールする。
4.サーバー：我々の場合はTomcat。

```java
    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 TestServlet 
     */  
    @WebServlet("/TestServlet")  
    public class TestServlet extends HttpServlet {  
        private static final long serialVersionUID = 1L;  
             
        /** 
         * @see HttpServlet#HttpServlet() 
         */  
        public TestServlet() {  
            super();  
            // TODO Auto-generated constructor stub  
        }  
      
        /** 
         * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) 
         */  
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  
            // TODO Auto-generated method stub  
            response.getWriter().append("Served at: ").append(request.getContextPath());  
        }  
      
        /** 
         * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) 
         */  
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  
            // TODO Auto-generated method stub  
            doGet(request, response);  
        }  
      
    }  
```
Crear una aplicación WEB en Java es una tarea complicada. Sin embargo, haré me mejor intento.

1. Instala Java
2. Instala IDE ( Eclipse o Netbeans)
3. Manejador de bases de datos como Oracle o Mysql
4. Un servidor: Tomcat en nuestro caso.

```java
    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 TestServlet 
     */  
    @WebServlet("/TestServlet")  
    public class TestServlet extends HttpServlet {  
        private static final long serialVersionUID = 1L;  
             
        /** 
         * @see HttpServlet#HttpServlet() 
         */  
        public TestServlet() {  
            super();  
            // TODO Auto-generated constructor stub  
        }  
      
        /** 
         * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) 
         */  
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  
            // TODO Auto-generated method stub  
            response.getWriter().append("Served at: ").append(request.getContextPath());  
        }  
      
        /** 
         * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) 
         */  
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  
            // TODO Auto-generated method stub  
            doGet(request, response);  
        }  
      
    }  
```