接続方法:getConnection()

	 //                   
	private static String url="jdbc:mysql://localhost:3306/test";
    private static String username="root";   
    private static String password="123456";   
    private Connection connection;    
    public  Connection getConnection(){ 
           try {
               connection= DriverManager.getConnection(url,username,password);
           } catch (SQLException e) {
               System.out.println("       ！");
           }
           return  connection;  
           }
    }