If you are talking about Connector/J, it provides:
com.mysql.jdbc.jdbc2.optional.MysqlDataSource
(which implements DataSource),
com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDataSource
(which implements ConnectionPoolDataSource)
com.mysql.jdbc.jdbc2.optional.MysqlXADataSource
(which implements XADataSource)
So, as far as your question goes. Yes Connector/J provides implementations to the DataSource
interface and conforms with JDBC specs.
But, as you are aware by your question and @Piotr's answer, most applications will never deal with those implementations directly. At least in ten years as a Java Developer I have never done that. Let the Java EE App Server handle connections for you, or install a third party connection pool if you are down to standalone applications.