Java 超过休眠锁等待超时;
我正在使用Hibernate,试图模拟对数据库中同一行的2次并发更新 编辑:我将em1.getTransaction().commit移动到em1.flush()之后;我没有收到任何StaleObjectException,这两个事务已成功提交Java 超过休眠锁等待超时;,java,hibernate,transactions,Java,Hibernate,Transactions,我正在使用Hibernate,试图模拟对数据库中同一行的2次并发更新 编辑:我将em1.getTransaction().commit移动到em1.flush()之后;我没有收到任何StaleObjectException,这两个事务已成功提交 Session em1=Manager.sessionFactory.openSession(); Session em2=Manager.sessionFactory.openSession(); em1.getTransaction().begin
Session em1=Manager.sessionFactory.openSession();
Session em2=Manager.sessionFactory.openSession();
em1.getTransaction().begin();
em2.getTransaction().begin();
UserAccount c1 = (UserAccount)em1.get( UserAccount.class, "root" );
UserAccount c2 = (UserAccount)em2.get( UserAccount.class, "root" );
c1.setBalance( c1.getBalance() -1 );
em1.flush();
System.out.println("balance1 is "+c2.getBalance());
c2.setBalance( c2.getBalance() -1 );
em2.flush(); // fail
em1.getTransaction().commit();
em2.getTransaction().commit();
System.out.println("balance2 is "+c2.getBalance());
我在em2.flush()
上遇到以下异常。为什么?
2009-12-23 21:48:37,648 WARN JDBCExceptionReporter:100 - SQL Error: 1205, SQLState: 41000
2009-12-23 21:48:37,649 ERROR JDBCExceptionReporter:101 - Lock wait timeout exceeded; try restarting transaction
2009-12-23 21:48:37,650 ERROR AbstractFlushingEventListener:324 - Could not synchronize database state with session
org.hibernate.exception.GenericJDBCException: Could not execute JDBC batch update
at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:126)
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:114)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:275)
at org.hibernate.persister.entity.AbstractEntityPersister.processGeneratedProperties(AbstractEntityPersister.java:3702)
at org.hibernate.persister.entity.AbstractEntityPersister.processUpdateGeneratedProperties(AbstractEntityPersister.java:3691)
at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:147)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:168)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1028)
at com.ch.whoisserver.test.StressTest.main(StressTest.java:54)
Caused by: java.sql.BatchUpdateException: Lock wait timeout exceeded; try restarting transaction
at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:1213)
at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:912)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)
... 10 more
好吧,你试图陷入僵局,你成功了:-)
我实际上是在写一个测试用例,看看乐观锁定是否有效,问题中的object UserAccount正在使用版本,请查看这个问题的详细信息,在这种情况下,如果使用两个线程,transaction2会得到staledObjectException来检测基础数据的更改吗?我已经更新了上面的答案-在步骤2中使用两个线程不是测试特定乐观锁定(由于不可预测)的好方法,你的意思是获取em2而不是获取em1吗?我想在em1.flush之后移动em1.commit应该足够了。是的,对不起。所有3个步骤都应该有3个不同的实体经理。