[hibernate] not-null property references a null or transient value

Facing trouble in saving parent/child object with hibernate. Any idea would be highly appreciated.

org.hibernate.PropertyValueException: not-null property references a null or transient value: example.forms.InvoiceItem.invoice
    at org.hibernate.engine.Nullability.checkNullability(Nullability.java:100)
        .... (truncated)

hibernate mapping:

<hibernate-mapping package="example.forms">
    <class name="Invoice" table="Invoices">
        <id name="id" type="long">
            <generator class="native" />
        </id>
        <property name="invDate" type="timestamp" />
        <property name="customerId" type="int" />
        <set cascade="all" inverse="true" lazy="true" name="items" order-by="id">
            <key column="invoiceId" />
            <one-to-many class="InvoiceItem" />
        </set>
    </class>
    <class name="InvoiceItem" table="InvoiceItems">
        <id column="id" name="itemId" type="long">
            <generator class="native" />
        </id>
        <property name="productId" type="long" />
        <property name="packname" type="string" />
        <property name="quantity" type="int" />
        <property name="price" type="double" />
        <many-to-one class="example.forms.Invoice" column="invoiceId" name="invoice" not-null="true" />
    </class>
</hibernate-mapping>

InvoiceManager.java

class InvoiceManager {

    public Long save(Invoice theInvoice) throws RemoteException {
        Session session = HbmUtils.getSessionFactory().getCurrentSession();
        Transaction tx = null;
        Long id = null;
        try {
            tx = session.beginTransaction();
            session.persist(theInvoice);
            tx.commit();
            id = theInvoice.getId();
        } catch (RuntimeException e) {
            if (tx != null)
                tx.rollback();
            e.printStackTrace();
            throw new RemoteException("Invoice could not be saved");
        } finally {
            if (session.isOpen())
                session.close();
        }
        return id;
    }
}

Invoice.java

public class Invoice implements java.io.Serializable {
    private Long id;
    private Date invDate;
    private int customerId;
    private Set<InvoiceItem> items;

    public Long getId() {
        return id;
    }
    public Date getInvDate() {
        return invDate;
    }
    public int getCustomerId() {
        return customerId;
    }
    public Set<InvoiceItem> getItems() {
        return items;
    }
    void setId(Long id) {
        this.id = id;
    }
    void setInvDate(Date invDate) {
        this.invDate = invDate;
    }
    void setCustomerId(int customerId) {
        this.customerId = customerId;
    }
    void setItems(Set<InvoiceItem> items) {
        this.items = items;
    }
}

InvoiceItem.java

public class InvoiceItem implements java.io.Serializable {
    private Long itemId;
    private long productId;
    private String packname;
    private int quantity;
    private double price;
    private Invoice invoice;

    public Long getItemId() {
        return itemId;
    }
    public long getProductId() {
        return productId;
    }
    public String getPackname() {
        return packname;
    }
    public int getQuantity() {
        return quantity;
    }
    public double getPrice() {
        return price;
    }
    public Invoice getInvoice() {
        return invoice;
    }
    void setItemId(Long itemId) {
        this.itemId = itemId;
    }
    void setProductId(long productId) {
        this.productId = productId;
    }
    void setPackname(String packname) {
        this.packname = packname;
    }
    void setQuantity(int quantity) {
        this.quantity = quantity;
    }
    void setPrice(double price) {
        this.price = price;
    }
    void setInvoice(Invoice invoice) {
        this.invoice = invoice;
    }
}

This could be as simple as:

@Column(name = "Some_Column", nullable = false)

but while persisting, the value of "Some_Column"is null, even if "Some_Column" may not be any primary or foreign key.

Make that variable as transient.Your problem will get solved..

@Column(name="emp_name", nullable=false, length=30)
    private transient String empName;

for followers, this error message can also mean "you have it referencing a foreign object that hasn't been saved to the DB yet" (even though it's there, and is non null).

Check the unsaved values for your primary key/Object ID in your hbm files. If you have automated ID creation by hibernate framework and you are setting the ID somewhere it will throw this error.By default the unsaved value is 0, so if you set the ID to 0 you will see this error.

I resolved by removing @Basic(optional = false) property or just update boolean @Basic(optional = true)

I was getting the same error but solved it finally,actually i was not setting the Object Entity which is already saved to the other entity and hence the Object value it was getting for foreeign key was null.