Primeiro banco de dados

import java.sql.*;   
  
  public class TestaConexao {
	 
	  public static void main (String args[])   
      
	  {   
  
        Connection con = null ; 
          
                
  
      try    
      {   
              
    	  Class.forName("com.mysql.jdbc.Driver");   
             
    	   con = DriverManager.getConnection("jdbc:mysql://localhost/banco?user=root&password=409827");   
          
          Statement stm = con.createStatement();     
      
   
          String SQL = "SELECT num from tabela";   
  
   
          ResultSet rs = stm.executeQuery(SQL);   
      
   
          while(rs.next())   
          {   
           int num = rs.getInt("num");
              System.out.println(num);  
          }   
  
      }   
      catch(SQLException e )    
      {   
                   e.printStackTrace();           
      }
      catch(ClassNotFoundException ex) {
    	  ex.printStackTrace();
      }
      finally  
      {   
         try    
         {   
            con.close();   
         }   
         catch(SQLException onConClose)   
         {   
             System.out.println("Houve erro no fechamento da conexão");   
             onConClose.printStackTrace();   
         }   
      } 
        
     
   }
}