I think you overdid the slashes in your URL, but that's a different problem.
First, check to make sure that the MySQL server is running (just in case!)
Secondly, check to see if it's listening on the tcp/ip port that your
JDBC driver is expecting to talk on (it may be 1033 for MySQL, but I'd check, 'cause I don't rightly remember). netstat is your friend.
Third, make sure MySQL wishes to talk to you. I think you can get a "connection refused" if it checks your host address and finds that that host isn't authorised to talk to the database you wish to use.
*** WARNING *** The messages that MySQL return in the above case LIE. MySQL does a reverse lookup on the incoming IP address and uses THAT hostname to validate, despite reporting the failure being against YOUR hostname.
r maybe it's vice versa. Every time I set up a MySQL server I get into fights with it over that. MySQL does provide a utility program to lookup hostnames, BTW. It can be used to help you.