怎么用jsp和servlet获得含有用户名 varchar 性别enum("1""2")和time datetime的预约信息表的信息，具体代码和文件

首先，你需要在数据库中创建一个名为“appointment”的表，该表应包含以下列：

- id：int类型，主键，自动递增
- username：varchar类型，表示预约者的用户名
- gender：enum类型，表示预约者的性别
- time：datetime类型，表示预约时间

接下来，你可以使用以下代码来编写一个Servlet，以获取预约信息表中的信息：

import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/appointment")
public class AppointmentServlet extends HttpServlet {
    
    private static final long serialVersionUID = 1L;
    private Connection conn;
    
    public void init() throws ServletException {
        try {
            Class.forName("com.mysql.jdbc.Driver");
            String url = "jdbc:mysql://localhost:3306/mydb";
            String username = "root";
            String password = "password";
            conn = DriverManager.getConnection(url, username, password);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        
        List<Appointment> appointments = new ArrayList<Appointment>();
        
        try {
            PreparedStatement ps = conn.prepareStatement("SELECT * FROM appointment");
            ResultSet rs = ps.executeQuery();
            
            while (rs.next()) {
                Appointment appointment = new Appointment();
                appointment.setId(rs.getInt("id"));
                appointment.setUsername(rs.getString("username"));
                appointment.setGender(rs.getString("gender"));
                appointment.setTime(rs.getString("time"));
                appointments.add(appointment);
            }
            
            rs.close();
            ps.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        
        request.setAttribute("appointments", appointments);
        request.getRequestDispatcher("/appointments.jsp").forward(request, response);
    }
    
    public void destroy() {
        try {
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

}

在本例中，我们使用MySQL数据库。如果你使用的是其他数据库，你需要更改驱动程序的名称和连接URL。

在JSP文件中，你可以使用以下代码来显示预约信息表中的信息：

<% List<Appointment> appointments = (List<Appointment>) request.getAttribute("appointments"); %>

<table>
    <thead>
        <tr>
            <th>ID</th>
            <th>Username</th>
            <th>Gender</th>
            <th>Time</th>
        </tr>
    </thead>
    <tbody>
        <% for (Appointment appointment : appointments) { %>
            <tr>
                <td><%= appointment.getId() %></td>
                <td><%= appointment.getUsername() %></td>
                <td><%= appointment.getGender() %></td>
                <td><%= appointment.getTime() %></td>
            </tr>
        <% } %>
    </tbody>
</table>

最后，你需要在web.xml文件中使用以下代码来映射Servlet：

<servlet>
    <servlet-name>AppointmentServlet</servlet-name>
    <servlet-class>com.example.AppointmentServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>AppointmentServlet</servlet-name>
    <url-pattern>/appointment</url-pattern>
</servlet-mapping>

请注意，你需要将这些代码添加到你的项目中，并将其配置为适合你的项目。