JAVA + JPA + JTable

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to Tabela.Packing at Tabela.ModelTabeli.getValueAt(ModelTabeli.java:36)

Packing p = (Packing) dane.get(rowIndex)

public class Packing {
    private String itemName;
    private String itemCode;
    private String certificateCode;
    private int itemQuantity;
    
    public void Packing()
    {
    }

    @Override
    public String toString() {
        return "Packing{" + "itemName=" + itemName + ", itemCode=" + itemCode + ", certificateCode=" + certificateCode + ", itemQuantity=" + itemQuantity + '}';
    }

    public String getItemName() {
        return itemName;
    }

    public void setItemName(String itemName) {
        this.itemName = itemName;
    }

    public String getItemCode() {
        return itemCode;
    }

    public void setItemCode(String itemCode) {
        this.itemCode = itemCode;
    }

    public String getCertificateCode() {
        return certificateCode;
    }

    public void setCertificateCode(String certificateCode) {
        this.certificateCode = certificateCode;
    }

    public int getItemQuantity() {
        return itemQuantity;
    }

    public void setItemQuantity(int itemQuantity) {
        this.itemQuantity = itemQuantity;
    }
}

public class Select {
    private static final String PERSISTENCE_UNIT_NAME = "TabelaPU";
    private EntityManagerFactory factory;
    
    EntityManager em = null;
    
    public List<Packing> Select(int id)
    {
        List<Packing> dane = null;
        try
        {
            factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
            em = factory.createEntityManager();
            em.getTransaction().begin();

            Query query = em.createQuery("SELECT pi.itemName, pi.itemCode, pi.certificateCode, "
                    + "pi.itemQuantity FROM PackingItem pi");
            dane = query.getResultList();
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
        
        return dane;
    }
}

public class ModelTabeli extends AbstractTableModel{
    private List<Packing> dane = null;
    
    final static Object[] columns = {"Item", "Index", "Certyfikat", "Ilość"};
    
    public ModelTabeli(){}

    @Override
    public int getRowCount() {
        if(dane==null) return 0;
        return dane.size();
    }

    @Override
    public int getColumnCount() {
        return columns.length;
    }
    
    @Override
    public Object getValueAt(int rowIndex, int columnIndex) {
        if(dane==null) return null;
        
        Packing p = (Packing) dane.get(rowIndex);             //linijka gdzie program się wysypuje
        switch(columnIndex){
            case 0:
                return p.getItemName();
            case 1:
                return p.getItemCode();
            case 2:
                return p.getCertificateCode();
            case 3:
                return p.getItemQuantity();
            default:
                return p;
        }
    }
    
    @Override
    public boolean isCellEditable(int row, int column) {
        return false;
    }
     
    public void setModelData(List<Packing> packing) {
       this.dane =  packing;
    }
    public Packing getPacking(int position) {
        return dane.get(position);
    }

    @Override
    public String getColumnName(int column) {
        return columns[column].toString();
    }
}

Select s = new Select();
        List<Packing> dane = new ArrayList<Packing>();
        dane = s.Select();
        ModelTabeli mt = new ModelTabeli();
        mt.setModelData(dane);
        jTable1.setModel(mt);

List<PackingAll> a1 = null;
Query query = em.createQuery("SELECT pi.idPackingItem, pi.itemName, pi.itemCode, pi.certificateCode, "
                    + "pi.letter, pi.goldLetter, pp.country, pi.itemQuantity, d.deliveryType, pi.envelopeCode, "
                    + "pi.additionalLetter, pp.packingNote FROM PackingItem pi "
                    + "JOIN pi.idPackingPackages AS pp JOIN pp.idDeliveryType AS d "
                    + "JOIN pp.idPackingFile AS pf JOIN pf.idPackingRun as pr WHERE pr.idPackingRun = :idPackingRun "
                    + "ORDER BY pp.country DESC, pi.itemCode ASC");
            query.setParameter("idPackingRun", _idRun);
            a1 = query.getResultList();

public class PackingAll {
    
    private int idPackingItem;
    private String itemName;
    private String itemCode;
    private String certificateCode;
    private String letter;
    private Boolean goldLetter;
    private String country;
    private int itemQuantity;
    private String deliveryType;
    private String envelopeCode;
    private String additionalLetter;
    private String packingNote;
    
    @Override
    public String toString() {
        return "PackingAll{" + "idPackingItem=" + idPackingItem + ", itemName=" + itemName + ", itemCode=" + itemCode + ", certificateCode=" + certificateCode + ", letter=" + letter + ", country=" + country + ", itemQuantity=" + itemQuantity + ", deliveryType=" + deliveryType + ", envelopeCode=" + envelopeCode + ", additionalLetter=" + additionalLetter + ", packingNote=" + packingNote + '}';
    }
    
    public void PackingAll()
    {
    }

    public int getIdPackingItem() {
        return idPackingItem;
    }

    public void setIdPackingItem(int idPackingItem) {
        this.idPackingItem = idPackingItem;
    }
    
    public int getItemQuantity() {
        return itemQuantity;
    }

    public void setItemQuantity(int itemQuantity) {
        this.itemQuantity = itemQuantity;
    }

    public String getItemName() {
        return itemName;
    }

    public void setItemName(String itemName) {
        this.itemName = itemName;
    }

    public String getItemCode() {
        return itemCode;
    }

    public void setItemCode(String itemCode) {
        this.itemCode = itemCode;
    }

    public String getCertificateCode() {
        return certificateCode;
    }

    public void setCertificateCode(String certificateCode) {
        this.certificateCode = certificateCode;
    }

    public String getLetter() {
        return letter;
    }

    public void setLetter(String letter) {
        this.letter = letter;
    }

    public Boolean getGoldLetter() {
        return goldLetter;
    }

    public void setGoldLetter(Boolean goldLetter) {
        this.goldLetter = goldLetter;
    }

    public String getCountry() {
        return country;
    }

    public void setCountry(String country) {
        this.country = country;
    }

    public String getDeliveryType() {
        return deliveryType;
    }

    public void setDeliveryType(String deliveryType) {
        this.deliveryType = deliveryType;
    }

    public String getEnvelopeCode() {
        return envelopeCode;
    }

    public void setEnvelopeCode(String envelopeCode) {
        this.envelopeCode = envelopeCode;
    }

    public String getAdditionalLetter() {
        return additionalLetter;
    }

    public void setAdditionalLetter(String additionalLetter) {
        this.additionalLetter = additionalLetter;
    }

    public String getPackingNote() {
        return packingNote;
    }

    public void setPackingNote(String packingNote) {
        this.packingNote = packingNote;
    }
    

}