No suitable driver found exception

Hello,

I have a simple java class (myTest.java) that I'm trying to run. This
class uploads an RDFS schema into a postgresql database using three
methods: setAuthentication, which specifies the username and password
used to gain access to the database, setDBFunctionsPath, which specifies
the library containing the functions to actually store the RDF, and
store, which takes as parameters the URL of the RDF schema to be loaded
into the database, and the URL of the database into which the schema
will be loaded. When I try to run the class, I'm getting the following
exception:
SQLException: No suitable driver
java.sql.SQLException: No suitable driver.

I have the postgresql.jar file in my classpath, as well the
jdbc7.1-1.2.jar which I downloaded from the postgresql.org's jdbc site.
I'm using Postgresql v7.1.3 and JDBC v2.0. I'd appreciate any
suggestions to resolve this issue that anyone has.

Thank you very much,
Amanda Martino
amartino@mitre.org