Question

我要从数据库中刷新Eleve列表到Jtable。 Jtable它的自我绑定到可观察的list< Eleve >，因此列表中的任何添加/删除都会在Jtable中自动更新。

我的代码解释了它的自我：

EleveJpaController ejc = new EleveJpaController(emf);
java.util.Collection<Eleve> data = ejc.findEleveByNiveauClasseNomPrenom(niv, classe, nom, prenom);

for (Eleve entity : data) {
    entityManager.refresh(entity);
}

list.clear();
list.addAll(data);

列表与LT; Eleve＆gt; findEleveByNiveauClasseNomPrenom（A，V，X，N）：

 public List<Eleve> findEleveByNiveauClasseNomPrenom(String niv,String classe,String nom, String prenom)
    {
        EntityManager em = getEntityManager();
        Query qr= em.createQuery("SELECT e FROM Eleve e WHERE e.niv.niv like '%"+niv+"%' and e.class1.libelle like '%"+classe+"%' and e.nom like '%"+nom+"%' and e.prenom like '%"+prenom+"%'");

       return qr.getResultList(); 
    }

正如您所看到的，它是Eleve对象的良好状态列表..那么为什么会抛出此异常？

[EL Info]: 2013-12-02 13:25:33.312--ServerSession(1903253526)--EclipseLink, version: Eclipse Persistence Services - 2.3.0.v20110604-r9504
[EL Info]: 2013-12-02 13:25:35.005--ServerSession(1903253526)--file:/C:/Users/marwen/Documents/NetBeansProjects/JocondeFinale/build/classes/_JocondeFinalePU login successful
Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: Can not refresh not managed object: entities.Eleve[ idEleve=7 ].
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.refresh(EntityManagerImpl.java:943)
    at org.eclipse.persistence.internal.jpa.EntityManagerImpl.refresh(EntityManagerImpl.java:849)
    at entities.GestionPaiement.niveauJcbbxItemStateChanged(GestionPaiement.java:736)
    at entities.GestionPaiement.access$2000(GestionPaiement.java:32)
    at entities.GestionPaiement$FormListener.itemStateChanged(GestionPaiement.java:607)
    at javax.swing.JComboBox.fireItemStateChanged(JComboBox.java:1225)
    at javax.swing.JComboBox.selectedItemChanged(JComboBox.java:1273)
    at javax.swing.JComboBox.contentsChanged(JComboBox.java:1329)
    at javax.swing.AbstractListModel.fireContentsChanged(AbstractListModel.java:118)
    at javax.swing.DefaultComboBoxModel.setSelectedItem(DefaultComboBoxModel.java:94)
    at javax.swing.JComboBox.setSelectedItem(JComboBox.java:578)
    at javax.swing.JComboBox.setSelectedIndex(JComboBox.java:624)
    at javax.swing.plaf.basic.BasicComboPopup$Handler.mouseReleased(BasicComboPopup.java:835)
    at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:290)
    at java.awt.Component.processMouseEvent(Component.java:6505)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
    at javax.swing.plaf.basic.BasicComboPopup$1.processMouseEvent(BasicComboPopup.java:499)
    at java.awt.Component.processEvent(Component.java:6270)
    at java.awt.Container.processEvent(Container.java:2229)
    at java.awt.Component.dispatchEventImpl(Component.java:4861)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
    at java.awt.Container.dispatchEventImpl(Container.java:2273)
    at java.awt.Window.dispatchEventImpl(Window.java:2719)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:694)
    at java.awt.EventQueue$3.run(EventQueue.java:692)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:708)
    at java.awt.EventQueue$4.run(EventQueue.java:706)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

干杯。

Answer 1

您可能正在使用不同的EntityManager来刷新您的实体，而不是从数据库加载实体的实体。实体不在新的EntityManager中进行管理。根据{{3}}，例外是非托管实体的正常行为。要么使用相同的EntityManager，要么使用javadoc来管理对象

Answer 2

这意味着，在调用entityManager.refresh(entity)时，您的实体不会由 EntityManager的实例管理，而不是由findEleveByNiveauClasseNomPrenom()中使用的entityManager管理。另一方面，你可能会问自己为什么要尝试刷新这些实体（你是否对它们进行了任何修改？）。

Answer 3

正如@Simiil所说，merge可以管理实体bean。

@Transactional
public void refresh(Entity entity) {
    final Entity e = getFacade().getEntityManager().merge(entity).;
    getFacade().getEntityManager().refresh(e); // you cannot use $entity because you need to use the brand new managed entity 
}

无法刷新未管理的对象

3 个答案: