Create a new database from JDBC?

How do I make a connection to a Postgresql database that (potentially)
has 0 databases from jdbc, so that I can issue a create database command?

In that _other_ database, I can make a jdbc connection to an address
like this:

jdbc:mysql://servername/

And then issue a "Create database foo" command.

Then I can reconnect to
jdbc:mysql://servername/foo

And everything is good.

If I try to connect to a postgresql database like this:

jdbc:postgresql://servername/

Postgres attempts to connect to a database that is named the same as the
username I provided.

Certainly not what I want, since that database doesn't exist.  Is there
a system database I could always count on being available that I could
connect to?

Thanks,

Dan

--
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Daniel Armbrust
Biomedical Informatics
Mayo Clinic Rochester
daniel.armbrust(at)mayo.edu
http://informatics.mayo.edu/