When I do the simple search from database, the java.lang.ArrayIndexOutOfBoundsException was Occured in Runtime.

public List findUncompletedGroups() throws LevelException{
List groupsIsUnCompleted;
try{
Session session = HibernateUtil.currentSession();
groupsIsUnCompleted = session.find("from Groups where TimeCompleted like '1970%' and levelID = ?", new Long(levelID), Hibernate.LONG);

}catch(Exception e){
throw new LevelException("Error in Level.findUncompletedGroups()" + e, e);
}

if(groupsIsUnCompleted == null){
throw new LevelException("Error in Level.findUncompletedGroups() groupsIsUnCompleted is null");
}else{
return groupsIsUnCompleted;
}
}