Oracle uses a jdbc URL of this form (presuming you are using the thin
drivers)
jdbc:oracle:thin:[<user>/<password>]@//<host>[:<port>]/<service>
where port is presumed to be 1521 if not specified

creating a connection  goes somethig like this

String url = "jdbc:oracle:thin:@//mydbhost/myschema";
String username = "dbuser";
String password= "dbpassword";

Class.forName("oracle.jdbc.OracleDriver");
Connection connection = DriverManager.getConnection(url, username,
password);