You'll have to configure the SQL Server so that it accepts TCP/IP connections. Make sure you know what port it's listening at, 2008 might decide to use a different port than 1433 (I have no idea whether it does or not). Configure a user ID and password for the database you want to connect to (also in the server) and use that user ID and password in your connection URL. Review the documentation to make sure your connection URL is formatted correctly.
Well the userName and password you have given are incorrect.
And better you use "SQL Server Authentication" mode when you are connecting through java.
but for that you need to enable TCP/IP Connection type.
For doing that, go to SQL Server Surface area configuration > Surface area configuration for Services And Connections > $Your_DB_Instance > Database Engine >Remote Connections
For understanding the differences between these two types please refer this
Use username sa and password which you have given at the time of instance creation. Please note that you can also reset the password for "sa" through windows authentication mode. So not a problem if you dont know the password.