本文介绍了非空属性引用空值或瞬态值的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述 面对使用Hibernate节省父/子对象的麻烦。任何想法将不胜感激。 org.hibernate.PropertyValueException：非空属性引用空值或瞬态值：示例。 forms.voiceItem.invoice
at org.hibernate.engine.Nullability.checkNullability（Nullability.java:100）
....（截断）
hibernate映射：
< hibernate-mapping package = example.forms >
< class name =Invoicetable =Invoices>
< id name =idtype =long>
< generator class =native/>
< / id>
< property name =invDatetype =timestamp/>
< property name =customerIdtype =int/>
< set cascade =allinverse =truelazy =truename =itemsorder-by =id>
< key column =invoiceId/>
< / set>
< / class>
< class name =InvoiceItemtable =InvoiceItems>
< id column =idname =itemIdtype =long>
< generator class =native/>
< / id>
< property name =productIdtype =long/>
< property name =packnametype =string/>
< property name =quantitytype =int/>
< property name =pricetype =double/>
< / 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;
尝试{
tx = session.beginTransaction（）;
session.persist（theInvoice）;
tx.commit（）;
id = theInvoice.getId（）;
} catch（RuntimeException e）{
if（tx！= null）
tx.rollback（）;
e.printStackTrace（）;
抛出新的RemoteException（发票无法保存）;
} finally {
if（session.isOpen（））
session.close（）;
}
return id;
$ / code $ / pre>
Invoice.java
public class Invoice implements java.io.Serializable {
private Long id;
私人日期invDate;
private int customerId;
private Set< InvoiceItem>项目;
public Long getId（）{
return id;
}
public Date getInvDate（）{
return invDate;
}
public int getCustomerId（）{
return customerId;
}
public Set< InvoiceItem> getItems（）{
返回项目;
}
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;
私人长期产品ID;
private String packname;
private int数量;
私人双重价格;
私人发票发票;
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发票getInvoice（）{
返回发票;
}
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;
}
}
解决方案 InvoiceItem 必须有一个发票，因为 not-null =true在多对一映射中。
所以基本的想法是你需要在代码中设置显式关系。有很多方法可以做到这一点。在你的课上，我看到一个 setItems 方法。我没有看到 addInvoiceItem 方法。设置项目时，您需要循环访问该组，并在所有项目上调用 item.setInvoice（this）。如果你实现了一个 addItem 方法，你需要做同样的事情。或者您需要另外设置集合中每个 InvoiceItem 的发票。
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;
}
}
解决方案 Every InvoiceItem must have an Invoice attached to it because of the not-null="true" in the many-to-one mapping.
So the basic idea is you need to set up that explicit relationship in code. There are many ways to do that. On your class I see a setItems method. I do NOT see an addInvoiceItem method. When you set items, you need to loop through the set and call item.setInvoice(this) on all of the items. If you implement an addItem method, you need to do the same thing. Or you need to otherwise set the Invoice of every InvoiceItem in the collection.
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