*
* @throws DatabaseConnectionException if the connection was already opened
* @return true if the connection is established correctly
* **/
public boolean openConnection() throws DatabaseConnectionException{
if(opened) throw new DatabaseConnectionException("The Connection was already opened");
else opened = true;
if(hibernateSession == null && hibernateEnabled){
SessionFactory session = hibernateUtility.getSessionFactory();
hibernateSession = session.getCurrentSession();