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我使用hibernate 4和spring-aop来处理事务,以便在服务器端总是有一个打开的事务。Hibernate嵌套事务/会话和代理关联
我想创建一个嵌套的事务来处理它,但我得到一个错误:非法尝试将代理与两个打开的会话关联。请参阅下面的示例:
实体e2使用持久实体e1中的数据创建并保存在嵌套事务中。 E1有一个深度图没有完全初始化。
在不抛出异常的情况下创建e2的正确方法是什么?
实施例方案:
---
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V
begin transaction 1
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---> Read persisted entity e1
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|
V
begin transaction 2
create new transient entity e2
copy properties from e1 to e2
save e2
-- THROWS Illegal attempt to associate a proxy with two open sessions --
commit transaction 2
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---------------
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V
commit transaction 1
代码例如:
@Test
public void testSaveInNestedSession() {
// open first session
Session session1 = sessionFactory.openSession();
Transaction transaction1 = session1.beginTransaction();
// get the existing music collection
MusicCollection mc = DbUtil.getMusicCollection(session1, "X Collection");
// create and save a copy of this collection in a nested transaction (will break)
replicateMusicCollection(mc);
transaction1.commit();
session1.close();
}
/**
* Save a copy of the MusicCollection in a new transaction
* for isolation purposes
* @param mc
*/
private void replicateMusicCollection(MusicCollection mc) {
// open nested session
Session session2 = sessionFactory.openSession();
Transaction transaction2 = session2.beginTransaction();
// create a new transient Music Collection
MusicCollection newMusic = new MusicCollection();
newMusic.setName("Collection Y");
newMusic.setOwner(mc.getOwner());
for(AudioCd cd : mc.getCdSet()) {
AudioCd newCd = new AudioCd();
newCd.setAlbumName(cd.getAlbumName());
newCd.setAuthor(cd.getAuthor());
newMusic.addAudioCd(newCd);
}
try {
session2.save(newMusic);
transaction2.commit();
}
catch(HibernateException e) {
e.printStackTrace();
transaction2.rollback();
throw e;
}
session2.close();
}
Maven项目与 [https://github.com/cemartins/test-cases]详细测试用例。