Spring中的Spring Data JPA存储库,事务和事件

在过去的几天中,试图解决以下问题的白发数量急剧增加.我在利用简单Spring 3.2事件机制的自定义事件侦听器中使用Spring Data JPA存储库.我遇到的问题是,如果ListenerA创建一个实体并调用assetRepository.save(entity)或assetRepository.saveAndFlash(entity),则从另一个侦听器检索此相同实体的后续调用将失败.原因似乎是ListenerB在数据库中找不到原始实体,它似乎仍在Hibernate的缓存中.
    ListenerB锁定实体的触发器是由于线程池中的可运行任务执行而触发的事件.
这是我的配置：

<bean id="entityManagerFactory"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="persistenceUnitName" value="spring-jpa" />
    <property name="jpaVendorAdapter">
        <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
            <property name="generateDdl" value="false" />
            <property name="database" value="#{appProps.database}" />
        </bean>
    </property>
    <property name="jpaProperties">
        <props>
            <prop key="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</prop>
            <prop key="hibernate.hbm2ddl.auto">#{appProps['hibernate.hbm2ddl.auto']}</prop>
            <prop key="hibernate.show_sql">#{appProps['hibernate.show_sql']}</prop>
            <prop key="hibernate.format_sql">#{appProps['hibernate.format_sql']}</prop>
            <prop key="hibernate.search.default.directory_provider">org.hibernate.search.store.impl.FSDirectoryProvider</prop>
            <prop key="hibernate.search.default.indexBase">#{appProps.indexLocation}</prop>
            <prop key="hibernate.search.lucene_version">#{appProps['hibernate.search.lucene_version']}</prop>
        </props>
    </property>
</bean>

<tx:annotation-driven transaction-manager="transactionManager" />

<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory" />
    <property name="jpaDialect">
        <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" />
    </property>
</bean>

我省略了dataSource配置,该配置是ComboPooledDataSource的实例,该实例定义了与Oracle数据库的连接.附带说明一下,使用了组件扫描,项目是Spring MVC.
现在是Java类.

听众A

@Sevice
public class ListenerA implements ApplicationListener<FileUploadedEvent> {

    @Autowired
    private AssetRepository assetRepository;

    @Autowired
    private ExecutorService executor; // Triggers runnable task on a Job in Spring's TaskExecutor

    @Override
    @Transactional
    public void onApplicationEvent(FileUploadedEvent event) {

    Asset target = event.getTarget();
    Job job = new Job(target);
    assetRepository.save(job);

    executor.execute(job);
}

侦听器B

@Sevice
public class ListenerB implements ApplicationListener<JobStartedEvent> {

    @Autowired
    private AssetRepository assetRepository;


    @Override
    @Transactional
    public void onApplicationEvent(JobStartedEvent event) {

    String id = event.getJobId();
    Job job = assetRepository.findOne(id); // at this point we can not find the job, returns null
    job.setStartTime(new DateTime());
    job.setStatus(Status.PROCESSING);

    assetRepository.save(job);
}

从TaskExecutor中的可运行任务触发JobStartedEvent.
我在这里做错了什么？我尝试使用具有事务意识的自定义事件发布者,但这似乎无法解决问题.我还尝试连接适当的服务而不是数据存储库,并从侦听器中删除@Transactional批注,这也失败了.任何有关解决问题的合理建议都将受到欢迎.

解决方法:

由于@Kresimir Nesek的提示,我设法解决了这个问题.因此,解决方案是用适当的服务替换Spring Data存储库.
这是修改后的类.

听众A

@Sevice
public class ListenerA implements ApplicationListener<FileUploadedEvent> {

    @Autowired
    private JobService service;

    @Autowired
    private ExecutorService executor; // Triggers runnable task on a Job in Spring's TaskExecutor

    @Override
    public void onApplicationEvent(FileUploadedEvent event) {

    Job job = service.initJobForExecution(event.getTarget());

    executor.execute(job);
    }
 }

在JobService方法中,必须使用@Transactional(propagation = Propagation.REQUIRES_NEW)注释initJobForExecution(资产目标).

听众B

@Sevice
public class ListenerB implements ApplicationListener<JobStartedEvent> {

@Autowired
private JobService service;


@Override
public void onApplicationEvent(JobStartedEvent event) {
    service.updateStatus(event.getJobId(), Status.PROCESSING); 
 }
}

标签：spring-data-jpa,event-handling,hibernate,spring,spring-mvc
来源： https://codeday.me/bug/20191123/2065862.html