mysql的Communications link failure

    刚开始学JDBC的使用，写了段代码：

public class TestJDBC2 {

	public static void main(String[] args) throws ClassNotFoundException, SQLException {
		Class.forName("com.mysql.jdbc.Driver");
		// DriverManager.registerDriver(new com.mysql.jdbc.Driver());

		String dbUrl = "jdbc:mysql://localhost:3302/mydata";
		String dbUser = "root";
		String dbPassword = "123456";

		Connection con = DriverManager.getConnection(dbUrl, dbUser, dbPassword);
		Statement stmt = con.createStatement();
		ResultSet rs = stmt.executeQuery("select * from users");

		while (rs.next()) {
			String col1 = rs.getString(1);
			String col2 = rs.getString(2);
			System.out.println(col1 + "  " + col2);

		}
		
		rs.close();
		stmt.close();
		con.close();

	}
}

 可是老是报“Communications link failure”错误，网上搜了下，走了很多弯路，最后终于发现了，，汗啊，原来写错端口号了，mysql的默认端口号是3306，不是3302啊，改好后就ok了。