由于新的HashSet,Spring Hibernate StaleObjectStateException？

Question

我的代码在很长一段时间内工作得很好,但经过几次重构之后,我注意到我突然无法再保存一个Group对象了.

我遇到了可怕的Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect)错误.谷歌搜索之后当然我发现了这个StackOverflow问题,但它根本没有帮助我,因为我没有同时做任何事情.

经过我的重构后,我发现的唯一区别就是这种变化.

之前:

    final Collection<Sample> allByBarcode = sampleService.byBarcode(groupRequest.getSamples(), currentUser);

    if (!allByBarcode.isEmpty()) {
        Group group = new Group();

        group.setName(groupRequest.getName());
        group.setSamples(allByBarcode);
        group.setType(groupRequest.getType());
        group.setOwner(currentUser);

        group = repository.save(group);

        return Optional.ofNullable(group);
    }

重构后(不记得具体原因)它成了:

    final Collection<Sample> allByBarcode = sampleService.byBarcode(groupRequest.getSamples(), currentUser);

    if (!allByBarcode.isEmpty()) {
        Group group = new Group();

        group.setName(groupRequest.getName());
        group.setSamples(new HashSet<>(allByBarcode));
        group.setType(groupRequest.getType());
        group.setOwner(currentUser);

        group = repository.save(group);

        return Optional.ofNullable(group);
    }

将它改回原来后,它每次都突然重新开始工作,没有任何错误.

任何人都可以解释这个错误的原因是什么,因为这实际上是代码中唯一的区别使它再次起作用？

更新1:

我尝试了另一种变体:

Group group = new Group();

group.setName(groupRequest.getName());
group.setSamples(new ArrayList<>(allByBarcode));
group.setType(groupRequest.getType());
group.setOwner(currentUser);

group = repository.save(group);

注意ArrayList而不是HashSet- 由于某种原因,此代码有效.

我也试过LinkedList这也适用.

有任何想法吗？

更新2:

堆栈跟踪如下:我已经删除它以删除大量的Spring和Tomcat相关的跟踪.

Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.orm.ObjectOptimisticLockingFailureException: Object of class [uk.ac.sanger.mig.aker.domain.Group] with identifier [93]: optimistic locking failed; nested exception is org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect) : [uk.ac.sanger.mig.aker.domain.Group#93]] with root cause

org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect) : [uk.ac.sanger.mig.aker.domain.Group#93]
        at org.hibernate.persister.entity.AbstractEntityPersister.check(AbstractEntityPersister.java:2541)
        at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:3285)
        at org.hibernate.persister.entity.AbstractEntityPersister.updateOrInsert(AbstractEntityPersister.java:3183)
        at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:3525)
        at org.hibernate.action.internal.EntityUpdateAction.execute(EntityUpdateAction.java:159)
        at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:465)
        at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:351)
        at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:350)
        at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:56)
        at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1222)
        at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:425)
        at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.beforeTransactionCommit(JdbcTransaction.java:101)
        at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.commit(AbstractTransactionImpl.java:177)
        at org.hibernate.jpa.internal.TransactionImpl.commit(TransactionImpl.java:77)
        at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:517)
        at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:757)
        at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:726)
        at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:521)
        at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:291)
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
        at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
        at com.sun.proxy.$Proxy116.createGroup(Unknown Source)
        at uk.ac.sanger.mig.aker.controllers.GroupController.store(GroupController.java:107)

Answer 1

我认为问题在于，您的集合 allByBarcode 中有一些重复的对象，当您将集合包装在不允许重复的 HashSet 中时，这些对象会消失。之后发生的情况是：您的存储库尝试多次保存同一对象。