how do I use sa to access local sql server database with jdbc

I have a new local sql server database, running hypothetically on port 48000. In SQL Server Management Studio under the name of the computer\MSSQLSERVER01, Security, Logins I clicked sa, properties and set the password. I have created a database, mystuff. sa is not listed under security under mystuff. I have the connection string jdbc:sqlserver://MYDESKTOP\MSSQLSERVER01:48000;databasename=mystuff;user=sa;password=123 but I get "Login failed for user 'sa'" when I attempt to connect. What else do I need to do to setup sa? Something under mystuff?