codice:
//String URL_DB = "jdbc:hsqldb={OpenDocument Database (*.odb)}; Dbq=/home/daniele/Desktop/prova.odb"; 
con = DriverManager.getConnection("jdbc:hsqldb://home/daniele/Desktop/prova.odb", "sa", ""); 
//con = DriverManager.getConnection(URL_DB, "sa", "");
devi utilizzare una cosa tipo questa..

http://hsqldb.org/