No suitable driver found for ‘jdbc:mysql://localhost:3306/mysql [duplicate]

In this particular case (assuming that the Class#forName() didn’t throw an exception; your code is namely continuing with running instead of throwing the exception), this SQLException means that Driver#acceptsURL() has returned false for any of the loaded drivers.

And indeed, your JDBC URL is wrong:

String url = "'jdbc:mysql://localhost:3306/mysql";

Remove the singlequote:

String url = "jdbc:mysql://localhost:3306/mysql";

See also:

• Mini tutorial on MySQL + JDBC connectivity