Question

我需要一个解决方案来更新实体而不使用EclipeLink 2.7进行选择。 Here我找到了以下解决方案：

EntityManager entityManager = entityManagerFactory.createEntityManager();
entityManager.getTransaction().begin();
UnitOfWork unitOfWork = ((EntityManagerImpl) entityManager.getDelegate()).getUnitOfWork();
AbstractSession session = unitOfWork.getParent();
session.updateObject(entity);
entityManager.getTransaction().commit();

这就是我得到的：

Caused by: java.lang.ClassCastException: org.eclipse.persistence.internal.sessions.IsolatedClientSession cannot be cast to org.eclipse.persistence.internal.sessions.UnitOfWorkImpl
    at org.eclipse.persistence.internal.jpa.metadata.listeners.BeanValidationListener.preUpdate(BeanValidationListener.java:90) ~[org.eclipse.persistence.jpa.jar:na]
    at org.eclipse.persistence.descriptors.DescriptorEventManager.notifyListener(DescriptorEventManager.java:726) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.descriptors.DescriptorEventManager.notifyEJB30Listeners(DescriptorEventManager.java:696) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.descriptors.DescriptorEventManager.executeEvent(DescriptorEventManager.java:233) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.internal.queries.DatabaseQueryMechanism.updateObjectForWrite(DatabaseQueryMechanism.java:901) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.queries.UpdateObjectQuery.executeCommit(UpdateObjectQuery.java:69) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.internal.queries.DatabaseQueryMechanism.executeWrite(DatabaseQueryMechanism.java:259) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.queries.WriteObjectQuery.executeDatabaseQuery(WriteObjectQuery.java:60) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:911) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.internal.sessions.AbstractSession.internalExecuteQuery(AbstractSession.java:3346) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1892) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1874) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1824) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.internal.sessions.AbstractSession.updateObject(AbstractSession.java:4324) ~[org.eclipse.persistence.core.jar:na]

我尝试添加到实体

@ExistenceChecking(ExistenceType.CHECK_CACHE)
public class MyEntity {...}

和

@ExistenceChecking(ExistenceType.ASSUME_EXISTENCE)
public class MyEntity {...}

然而，它没有帮助。如何在EclipseLink 2.7中进行更新而不进行选择？

修改
我也试过

EntityManager entityManager = entityManagerFactory.createEntityManager();
entityManager.getTransaction().begin();
UpdateObjectQuery updateQuery= new UpdateObjectQuery();
updateQuery.setObject(entity);
Session session = ((JpaEntityManager)entityManager.getDelegate()).getUnitOfWork().getParent();
session.executeQuery(updateQuery);
entityManager.getTransaction().commit();
entityManager.close();

但得到了：

Caused by: java.lang.ClassCastException: org.eclipse.persistence.internal.sessions.IsolatedClientSession cannot be cast to org.eclipse.persistence.internal.sessions.UnitOfWorkImpl
    at org.eclipse.persistence.internal.jpa.metadata.listeners.BeanValidationListener.preUpdate(BeanValidationListener.java:90) ~[org.eclipse.persistence.jpa.jar:na]
    at org.eclipse.persistence.descriptors.DescriptorEventManager.notifyListener(DescriptorEventManager.java:726) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.descriptors.DescriptorEventManager.notifyEJB30Listeners(DescriptorEventManager.java:696) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.descriptors.DescriptorEventManager.executeEvent(DescriptorEventManager.java:233) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.internal.queries.DatabaseQueryMechanism.updateObjectForWrite(DatabaseQueryMechanism.java:901) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.queries.UpdateObjectQuery.executeCommit(UpdateObjectQuery.java:69) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.internal.queries.DatabaseQueryMechanism.executeWrite(DatabaseQueryMechanism.java:259) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.queries.WriteObjectQuery.executeDatabaseQuery(WriteObjectQuery.java:60) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:911) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.internal.sessions.AbstractSession.internalExecuteQuery(AbstractSession.java:3346) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1892) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1874) ~[org.eclipse.persistence.core.jar:na]
    at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1824) ~[org.eclipse.persistence.core.jar:na]

Answer 1

JPA merge是一个特定的API，要求提供程序从缓存或数据库中提取对象的实例，然后将实例的更改合并到其中。

  UpdateObjectQuery updateQuery= new UpdateObjectQuery();
  updateQuery.setObject(myEntityInstance);
  Session session = ((JpaEntityManager)em.getDelegate()).getUnitOfWork().getParent();

  updated = (MyEntity)session.executeQuery(updateQuery);

当我知道对象已经存在并且不介意在update语句中包含所有字段时，

而不是合并。这允许我在之前已经在此上下文中读取此实例时在其他用例中使用merge，或者我需要确保仅更新更新的字段。

Answer 2

@Chris在评论中指出有必要关闭bean验证。所以我在persistence.xml中添加了以下行

<property name="javax.persistence.validation.mode" value="none"/>

问题解决了。

在EclipseLink 2.7中不选择更新

2 个答案: