如何在@Transactional方法中手动强制提交？

java spring jpa spring-data spring-transactions

2022-08-31 13:39:28

我正在使用Spring / Spring-data-JPA，发现自己需要在单元测试中手动强制提交。我的用例是，我正在做一个多线程测试，在这个测试中，我必须使用在生成线程之前持久化的数据。

不幸的是，假设测试是在事务中运行的，即使是 a 也不会使生成的线程可以访问它。@Transactionalflush

   @Transactional   
   public void testAddAttachment() throws Exception{
        final Contract c1 = contractDOD.getNewTransientContract(15);
        contractRepository.save(c1);

        // Need to commit the saveContract here, but don't know how!                
        em.getTransaction().commit();

        List<Thread> threads = new ArrayList<>();
        for( int i = 0; i < 5; i++){
            final int threadNumber = i; 
            Thread t =  new Thread( new Runnable() {
                @Override
                @Transactional
                public void run() {
                    try {
                        // do stuff here with c1

                        // sleep to ensure that the thread is not finished before another thread catches up
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            });
            threads.add(t);
            t.start();
        }

        // have to wait for all threads to complete
        for( Thread t : threads )
            t.join();

        // Need to validate test results.  Need to be within a transaction here
        Contract c2 = contractRepository.findOne(c1.getId());
    }

我已尝试使用实体管理器，但在执行此操作时收到错误消息：

org.springframework.dao.InvalidDataAccessApiUsageException: Not allowed to create transaction on shared EntityManager - use Spring transactions or EJB CMT instead; nested exception is java.lang.IllegalStateException: Not allowed to create transaction on shared EntityManager - use Spring transactions or EJB CMT instead
    at org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:293)
    at org.springframework.orm.jpa.aspectj.JpaExceptionTranslatorAspect.ajc$afterThrowing$org_springframework_orm_jpa_aspectj_JpaExceptionTranslatorAspect$1$18a1ac9(JpaExceptionTranslatorAspect.aj:33)

有没有办法提交交易并继续它？我一直找不到任何允许我调用.commit()

答案 1

在测试休眠事件侦听器期间，我有一个类似的用例，这些侦听器仅在提交时调用。

解决方案是将要持久的代码包装到另一个带有注释的方法中。（在另一个班级）这样，将生成一个新事务，并在方法返回后发出刷新/提交。REQUIRES_NEW

Tx prop REQUIRES_NEW

请记住，这可能会影响所有其他测试！因此，请相应地编写它们，否则您需要确保在测试运行后可以清理。

答案 2

你为什么不使用spring的TranschangeTemplate来以编程方式控制交易呢？你也可以重构你的代码，以便每个“交易块”都有自己的方法，但考虑到这是一个测试，我会选择对你的交易进行编程控制。@Transactional

另请注意，运行对象上的@Transactional注释将不起作用（除非您使用的是 aspectj），因为 runnables 不受 spring 管理！

@RunWith(SpringJUnit4ClassRunner.class)
//other spring-test annotations; as your database context is dirty due to the committed transaction you might want to consider using @DirtiesContext
public class TransactionTemplateTest {

@Autowired
PlatformTransactionManager platformTransactionManager;

TransactionTemplate transactionTemplate;

@Before
public void setUp() throws Exception {
    transactionTemplate = new TransactionTemplate(platformTransactionManager);
}

@Test //note that there is no @Transactional configured for the method
public void test() throws InterruptedException {

    final Contract c1 = transactionTemplate.execute(new TransactionCallback<Contract>() {
        @Override
        public Contract doInTransaction(TransactionStatus status) {
            Contract c = contractDOD.getNewTransientContract(15);
            contractRepository.save(c);
            return c;
        }
    });

    ExecutorService executorService = Executors.newFixedThreadPool(5);

    for (int i = 0; i < 5; ++i) {
        executorService.execute(new Runnable() {
            @Override  //note that there is no @Transactional configured for the method
            public void run() {
                transactionTemplate.execute(new TransactionCallback<Object>() {
                    @Override
                    public Object doInTransaction(TransactionStatus status) {
                        // do whatever you want to do with c1
                        return null;
                    }
                });
            }
        });
    }

    executorService.shutdown();
    executorService.awaitTermination(10, TimeUnit.SECONDS);

    transactionTemplate.execute(new TransactionCallback<Object>() {
        @Override
        public Object doInTransaction(TransactionStatus status) {
            // validate test results in transaction
            return null;
        }
    });
}

}