Problema com armazenagem de dados

public Object[] getAll() throws FloggyException {

        System.out.println("JazidaDAO.getAll()");
        ObjectSet jazidas = PersistableManager.getInstance().find(Jazida.class, null, null);
        Vector jazidaList = null;
        for (int i = 0; i < jazidas.size(); i++) {
            if (jazidaList == null) {
                jazidaList = new Vector(jazidas.size());
            }
            Jazida jazida = (Jazida) jazidas.get(i);  //aqui dah o erro jazidas.get(i)
            jazidaList.addElement(jazida);
        }

        Jazida[] jazidaArray = null;
        if (jazidaList != null) {
            jazidaList.copyInto(jazidaArray = new Jazida[jazidaList.size()]);
        }
        return jazidaArray;
    }