[英]Hibernate threw org.hibernate.LazyInitializationException
After trying to populate javaFX table view with Purchase Object from database using hibernate. 尝试使用Hibernate从数据库中的Purchase Object填充javaFX table view之后。 To clarify thing a little, i have Purchase and Product entities related with many to many relationship, i have applied this methode [my own code] ( Hibernate many to many relationship with extras columns ) to map this relationship.
为了澄清一点,我具有与多对多关系相关的Purchase和Product实体,我已经将此方法(我自己的代码)( 用Extras列休眠了多对多关系 )来映射此关系。 I get this error:
我收到此错误:
Caused by: org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: model.Purchase.lineItems, could not initialize proxy - no Session
at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:567)
at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:205)
at org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:546)
at org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:133)
at org.hibernate.collection.internal.PersistentSet.iterator(PersistentSet.java:163)
at java.util.AbstractCollection.addAll(AbstractCollection.java:343)
at javafx.collections.ModifiableObservableListBase.addAll(ModifiableObservableListBase.java:99)
at controller.purchase.PurchaseController.setPurchaseHeader(PurchaseController.java:254)
at controller.purchase.PurchaseController.btnEditClicked(PurchaseController.java:244)
THIS THE CODE WHERE I GET ALL PURCHASE FROM DATABASE: Notice that i fill a tableView with thoes element, and for each Purchase with have LineItems. 在此代码中,我可以从数据库中获取所有购买商品:请注意,我用thoes元素填充了tableView,对于每个有LineItems的购买商品。
public ObservableList<Purchase> findAll() {
try {
if (!session.isOpen())
session = DatabaseUtil.getSessionFactory().openSession();
session.beginTransaction();
Criteria c = session.createCriteria(Purchase.class);
c.setFetchMode("lineItems", FetchMode.JOIN);
Query query = session.createQuery(" from Purchase ");
ObservableList<Purchase> list = FXCollections.observableArrayList(query.list());
session.getTransaction().commit();
session.close();
return list;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
It happens because you are trying to access these lineItems collection outside a Session context, and these lineItems objects were not brought by the actual query you used to fetch the Purchase(s) 发生这种情况是因为您试图在Session上下文之外访问这些lineItems集合,并且这些lineItems对象不是您用于获取购买商品的实际查询所带来的
Somewhere in you hibernate code that does the selection for your Purchase items you are supposed to add a fetch join mode for these lineItems 休眠代码中用于选择“购买”项目的某个位置,您应该为这些lineItem添加获取联接模式
Like : 喜欢 :
Criteria c = sessionFactory.getCurrentSession().createCriteria(Purchase.class);
c.setFetchMode("lineItems", FetchMode.JOIN);
After reading your code, I'd suggest something like: 阅读您的代码后,我建议如下所示:
public List<Purchase> findAll() {
try {
if (!session.isOpen())
session = DatabaseUtil.getSessionFactory().openSession();
session.beginTransaction();
Criteria c = session.createCriteria(Purchase.class);
c.setFetchMode("lineItems", FetchMode.JOIN);
List<Purchase> list = (List<Purchase>)c.list();
session.close();
return list;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
And then wrap your List into another ObservableList outside this call call 然后将您的列表包装到此调用之外的另一个ObservableList中
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