java – Hibernate将对象保存到多个会话

我试图使用hibernate写入多个数据库.我在单个会话对象中封装了写入和读取/写入会话.但是,当我去保存时,我收到很多错误,表明对象已经与另一个会话相关联：“非法尝试将集合与两个打开的会话相关联”

这是我的代码：

public class MultiSessionObject implements Session {       private Session writeOnlySession;       private Session readWriteSession;       @Override       public void saveOrUpdate(Object arg0) throws HibernateException {              readWriteSession.saveOrUpdate(arg0);              writeOnlySession.saveOrUpdate(arg0);       }}

我试过驱逐物体并冲洗;但是,这会导致“Row被另一个事务更新或删除”的问题……即使两个会话都指向不同的数据库.

public class MultiSessionObject implements Session {       private Session writeOnlySession;       private Session readWriteSession;       @Override       public void saveOrUpdate(Object arg0) throws HibernateException {              readWriteSession.saveOrUpdate(arg0);              readWriteSession.flush();              readWriteSession.evict(arg0);              writeOnlySession.saveOrUpdate(arg0);              writeOnlySession.flush();              writeOnlySession.evict(arg0);       }}

除了上述内容之外,我还尝试使用hibernate的复制功能.这也没有成功,没有错误.

有没有人成功将对象保存到两个具有相同模式的数据库中？

解决方法:

saveOrUpdate尝试将给定的Entity重新附加到当前运行的Session,因此Proxies(LAZY association)绑定到Hibernate Session.尝试使用merge instead of saveOrUpdate,因为merge只是将分离的实体状态复制到新检索的托管实体.这样,提供的参数永远不会附加到Session.

另一个问题是交易管理.如果您使用线程绑定事务,那么如果要从同一个线程更新两个DataSource,则需要两个显式事务.

尝试也明确设置事务边界：

public class MultiSessionObject implements Session {   private Session writeOnlySession;   private Session readWriteSession;   @Override   public void saveOrUpdate(Object arg0) throws HibernateException {        Transaction readWriteSessionTx = null;        try {            readWriteSessionTx = readWriteSession.beginTransaction();            readWriteSession.merge(arg0);            readWriteSessionTx.commit();        } catch (RuntimeException e) {            if ( readWriteSessionTx != null && readWriteSessionTx.isActive() )                 readWriteSessionTx.rollback();            throw e;        }        Transaction writeOnlySessionTx = null;        try {            writeOnlySessionTx = writeOnlySession.beginTransaction();            writeOnlySession.merge(arg0);            writeOnlySessionTx.commit();        } catch (RuntimeException e) {            if ( writeOnlySessionTx != null && writeOnlySessionTx.isActive() )                 writeOnlySessionTx.rollback();            throw e;        }   }}

来源：https://www.icode9.com/content-1-485451.html