尝试设置锁定(悲观)时,使用以下代码:
em.lock(controlnumbers, LockModeType.WRITE);
em.refresh(controlnumbers);
我收到以下异常:
[#|2009-09-10T15:42:48.324-0400|INFO|sun-appserver2.1|javax.enterprise.system.container.ejb|_ThreadID=31;_ThreadName=httpSSLWorkerThread-8080-19;|
javax.ejb.TransactionRolledbackLocalException: Exception thrown from bean; nested exception is: javax.persistence.PersistenceException: ejb30-wrong-lock_called_without_version_locking-index (There is no English translation for this message.)
javax.persistence.PersistenceException: ejb30-wrong-lock_called_without_version_locking-index (There is no English translation for this message.)
at oracle.toplink.essentials.internal.ejb.cmp3.base.EntityManagerImpl.lock(EntityManagerImpl.java:619)
at com.sun.enterprise.util.EntityManagerWrapper.lock(EntityManagerWrapper.java:582)
at com.eximtechnologies.transactionserver.persistence.session.ControlNumbersFacade.lock(ControlNumbersFacade.java:43)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
如何使用Glassfish 2.1实现悲观锁定?
答案 0 :(得分:2)
有一种Toplink Essentials(GF 2.1默认)具体方法:
public MyObject lock (MyObject controlnumbers) {
String qStr = "select object(o) from MyObject as o where o.pk = :pk";
Query q = em.createQuery(qStr);
q.setParameter("pk", "a");
q.setHint("toplink.pessimistic-lock", "Lock");
controlnumbers = (MyObject)q.getSingleResult();
return controlnumbers;
}
我相信使用Hibernate调用em.lock实际上会有效。
答案 1 :(得分:0)
你能展示你班级的地图吗?看起来你错过了一个版本属性......看看
http://en.wikibooks.org/wiki/Java_Persistence/Locking#Timestamp_Locking
问候,Jan