我是初学者大家看看我的代码有什么问题

Question

import javax.servlet.*;
import javax.servlet.http.*;
import javax.sql.*;
import javax.naming.*;
import java.sql.*;
import java.iol.IOException;public class TestServlet extends HttpServlet
{
    private Connection conn;    protected void doGet(HttpServletRequest req,HttpServletResponse res)
                                                   throws IOException,ServletException
    {
         try
         {
             Class.forName("COM.ibm.db2.jdbc.app.DB2Driver");
             conn=DriverManager.getConnection("jdbc:db2:mydb","db2","db2");
             PreparedStatement stmt=conn.prepareStatement("delete from mytb where id=?");
             for(int i=0;i<5;i++{
                 stmt.setInt(1,i);
                 stmt.executeUpdate();
               }
             conn.close;
         }
    }
    catch(Exception ex)
    {
        ex.printStackTrace();
    }
}
}

Answer 1

("delete from mytb where id='?'");