Question

我遇到一个Spring启动应用程序的问题，它在@Async任务（使用EntityManager）完成之前关闭了EntityManager /会话。

有两个与此问题相关的课程：

计划

预定方法会保留有限数量的作业，并在执行实际工作的@Async上调用XYJobProcessor方法。

@Component
public class XYJobProcessingTimer {

    private final XYJobService      xyJobService;
    private final XYJobProcessor    xyJobProcessor;

    //constructor skipped

    @Scheduled(initialDelayString = "${initial_delay}", fixedDelayString = "${delay}")
    public void performXYJobProcessing() {
        final String ticket = UUID.randomUUID().toString();
        final int reservedJobs = xyJobService.findAndReserveReadyXYJobs(ticket);

        if (reservedJobs > 0) {
            final Collection<XYJob> xyJobs = xyJobService.readReservedJobs(ticket);
            xyJobProcessor.process(xyJobs);
        }
    }

}

异步处理器

@Async带注释的方法调用访问EntityManager的服务。

@Service
public class XYJobProcessor {

    private final XYJobService  xyJobService;

    // constructor skipped

    @Async("xyJobProcessorExecutor")
    public void process(final Collection<XYJob> jobs) {
        // This service uses the EntityManager and takes some time depending o job count.
        xyJobService.createXYJobsAndDelete(jobs);
    }

}

配置

运行Executor任务的@Async的配置。创建的Threads是非守护进程。

@Configuration
public class AsyncExecutorConfiguration {

    @Bean(name = "xyJobProcessorExecutor")
    public Executor xyJobProcessorExecutor() {
        final SimpleAsyncTaskExecutor executor = new SimpleAsyncTaskExecutor();
        executor.setConcurrencyLimit(10);
        executor.setThreadNamePrefix("Hasselhoff-");
        return executor;
    }

}

问题

当我关闭应用程序时，spring会立即关闭EntityManager会话 - 在所有@Async任务完成之前。这导致以下异常：

2017-08-31 16:10:54.212 ERROR 12663 --- [Hasselhoff-12] .a.i.SimpleAsyncUncaughtExceptionHandler : Unexpected error occurred invoking async method 'public void de.xy.services.XYJobProcessor.process(java.util.Collection)'.org.springframework.orm.jpa.JpaSystemException: Session is closed!; nested exception is org.hibernate.SessionException: Session is closed!
        at org.springframework.orm.jpa.vendor.HibernateJpaDialect.convertHibernateAccessException(HibernateJpaDialect.java:333)
        at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:244)
        at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:521)
        at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:761)
        at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:730)
        at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:504)
        at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:292)
        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.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:673)
        at de.xy.services.XYJobService$$EnhancerBySpringCGLIB$$6b9cb1ae.createXYJobsAndDelete(<generated>)
        at de.xy.services.XYJobProcessor.process(XYJobProcessor.java:24)
        at de.xy.services.XYJobProcessor$$FastClassBySpringCGLIB$$ccc40c8f.invoke(<generated>)
        at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:738)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
        at org.springframework.aop.interceptor.AsyncExecutionInterceptor$1.call(AsyncExecutionInterceptor.java:115)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at org.springframework.core.task.SimpleAsyncTaskExecutor$ConcurrencyThrottlingRunnable.run(SimpleAsyncTaskExecutor.java:268)
        at java.lang.Thread.run(Thread.java:748)
Caused by: org.hibernate.SessionException: Session is closed!
        at org.hibernate.internal.AbstractSessionImpl.errorIfClosed(AbstractSessionImpl.java:132)
        at org.hibernate.internal.SessionImpl.getPersistenceContext(SessionImpl.java:2088)
        at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:340)
        at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:39)
        at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1282)
        at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:465)
        at org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:2963)
        at org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2339)
        at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:485)
        at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:147)
        at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access$100(JdbcResourceLocalTransactionCoordinatorImpl.java:38)
        at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:231)
        at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:65)
        at org.hibernate.jpa.internal.TransactionImpl.commit(TransactionImpl.java:61)
        at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:517)
        ... 17 common frames omitted

有没有办法让Spring在关闭EntityManager之前等待@Async执行完成？或者这是一个错误吗？

Answer 1

感谢@ M.Deinum，我发现了如何避免这个问题：

使用ThreadPoolTaskExecutor（而不是SimpleAsyncTaskExecutor）并将其awaitTerminationSeconds属性设置为waitForTasksToCompleteOnShutdown设置为true可以解决我的问题

来自setAwaitTerminationSeconds的JavaDoc：

设置此执行程序的最大秒数关闭时阻止以等待剩余任务完成在容器的其余部分继续关闭之前执行它们下。如果您的剩余任务很可能，这尤其有用需要访问同样由其管理的其他资源容器

这是我的问题的确切描述和解决方案。

Spring Boot在关闭时关闭hibernate会话 - 在@Async方法完成之前

1 个答案: