java - 如何获得事务回滚和对象的初始状态退休

Question

我不确定这是否正确，但我需要在事务回滚后，我的对象返回其初始状态。我创建了一个 junit 测试，但它失败了。

try {
    entityManager.getTransaction().begin();
    entityManager.persist(itemBec);
    //            throw new Exception("teste");
    //            throw new EJBTransactionRolledbackException("teste");
    //            throw new ConstraintViolationException("teste", null, null);
    throw new RuntimeException("teste");
} catch (Exception e) {
    entityManager.getTransaction().rollback();
} finally {
    if (entityManager.getTransaction().isActive()) {
        entityManager.getTransaction().commit();
    }
}
entityManager.close();
factory.close();
Assert.assertNull(itemBec.getId());

我假设对象必须返回其初始状态是否错误？

谢谢。

Answer 1

Am I wrong to assume that the object must return do its initial state?

Hibernate 不会回滚对象状态。最好不要跨事务重用对象，这样就不会出现这样的问题。

来自 this answer引用 spec (重点是我的):

Transaction Rollback

For both transaction-scoped and extended persistence contexts, transaction rollback causes all pre-existing managed instances and removed instances [31] to become detached. The instances’ state will be the state of the instances at the point at which the transaction was rolled back. Transaction rollback typically causes the persistence context to be in an inconsistent state at the point of rollback. In particular, the state of version attributes and generated state (e.g., generated primary keys) may be inconsistent. Instances that were formerly managed by the persistence context (including new instances that were made persistent in that transaction) may therefore not be reusable in the same manner as other detached objects—for example, they may fail when passed to the merge operation. [32]

这就是为什么我认为最好不要跨事务重用实体:虽然只要事务成功提交它就可以工作，但如果事务失败，事情就会变得更加复杂。通常，无论如何都没有令人信服的理由来跨事务重用实体。