This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Do you want several connections to the same database with the same login credentials? That is what you have. Or if the literal strings you posted were just examples, then you have a fixed number of connections.
I would have changed the makeConnection() method to pass the URL, username and password strings, and had the DriverManager.getConnection() method used the passed arguments. Or I would have wrapped all of this in a Connection wrapper class. Then each connection could use a different database and different credentials.