java - 合并后无法删除分离的实体()

Question

我在尝试删除实体时遇到问题，这是我的代码:

  @Transactional
  private <K> void delete(String type, EntityWithId<K> entity) {
    try {
      em.remove(em.contains(entity) ? entity : em.merge(entity));
    } catch (Exception e) {
      logger.warn("Unable to delete " + type + " with id " + entity.getId());
    }
  }

我不太明白为什么，但是删除语句失败，抛出

java.lang.IllegalArgumentException: Removing a detached instance

实体管理器不包含实体，所以每次都会执行merge()，remove总是失败，传递的对象不一样。

我做错了什么吗？

这是捕获异常的 StackTrace:

Unable to delete log with id 14091612
java.lang.IllegalArgumentException: Removing a detached instance myproj.jpa.AdvertisementLog#14091612
    at org.hibernate.ejb.event.EJB3DeleteEventListener.performDetachedEntityDeletionCheck(EJB3DeleteEventListener.java:67)
    at org.hibernate.event.internal.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:107)
    at org.hibernate.event.internal.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:74)
    at org.hibernate.internal.SessionImpl.fireDelete(SessionImpl.java:822)
    at org.hibernate.internal.SessionImpl.delete(SessionImpl.java:801)
    at org.hibernate.ejb.AbstractEntityManagerImpl.remove(AbstractEntityManagerImpl.java:880)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:365)
    at com.sun.proxy.$Proxy59.remove(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:240)
    at com.sun.proxy.$Proxy59.remove(Unknown Source)
    at myproj.batch.impl.DeleteOldAdvertisementsImpl.delete(DeleteOldAdvertisementsImpl.java:93)
    at myproj.batch.impl.DeleteOldAdvertisementsImpl.deleteAll(DeleteOldAdvertisementsImpl.java:86)
    at myproj.batch.impl.DeleteOldAdvertisementsImpl.deleteAll(DeleteOldAdvertisementsImpl.java:80)
    at myproj.batch.impl.DeleteOldAdvertisementsImpl.deleteAd(DeleteOldAdvertisementsImpl.java:69)
    at myproj.batch.impl.DeleteOldAdvertisementsImpl.clean(DeleteOldAdvertisementsImpl.java:54)
    at myproj.batch.main.DeleteOldAdvertisementsMain.main(DeleteOldAdvertisementsMain.java:13)

Answer 1

我看到注解在一个私有(private)方法上，所以它是从类中调用的。这个类是@Service类吗？您能否提供有关内部调用删除函数的方法的更多详细信息。私有(private)/ protected 方法忽略 Spring Transactional 注释。它们仅支持公共(public)方法。

编辑

仅将方法公开是不够的，bean 的入口点是什么(您从哪里调用该私有(private)方法)？如果该入口方法不是从 spring bean 调用的(例如，从 Autowiring 的字段)并且没有使用 @Transactional 注释，那么这就是问题的原因。