How to manually force a commit in a Transactional method

Question

I m using Spring   Spring-data-JPA and find myself needing to manually force a commit in a unit test   My use case is that I am doing a multi-threaded test in which I have to use data that is persisted before the threads are spawned   Unfortunately  given that the test is running in a  Transactional transaction  even a flush does not make it accessible to the spawned threads       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 lt Thread gt  threads   new ArrayList lt  gt             for  int i   0  i  lt  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             I ve tried using the entity manager to  but get an error message when I do   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    Is there any way to commit the transaction and continue it   I have been unable to find any method that allows me to call a commit

User · Accepted Answer

I had a similar use case during testing hibernate event listeners which are only called on commit.

The solution was to wrap the code to be persistent into another method annotated with REQUIRES_NEW. (In another class) This way a new transaction is spawned and a flush/commit is issued once the method returns.

Tx prop REQUIRES_NEW

Keep in mind that this might influence all the other tests! So write them accordingly or you need to ensure that you can clean up after the test ran.

User · Answer

Why don t you use spring s TransactionTemplate to programmatically control transactions  You could also restructure your code so that each  transaction block  has it s own  Transactional method  but given that it s a test I would opt for programmatic control of your transactions    Also note that the  Transactional annotation on your runnable won t work  unless you are using aspectj  as the runnables aren t managed by spring    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 lt Contract gt               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  lt  5    i            executorService execute new Runnable                  Override    note that there is no  Transactional configured for the method             public void run                     transactionTemplate execute new TransactionCallback lt Object gt                           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 lt Object gt               Override         public Object doInTransaction TransactionStatus status                   validate test results in transaction             return null

User · Answer

I know that due to this ugly anonymous inner class usage of TransactionTemplate doesn t look nice  but when for some reason we want to have a test method transactional IMHO it is the most flexible option   In some cases  it depends on the application type  the best way to use transactions in Spring tests is a turned-off  Transactional on the test methods  Why  Because  Transactional may leads to many false-positive tests  You may look at this sample article to find out details  In such cases TransactionTemplate can be perfect for controlling transaction boundries when we want that control

[java] How to manually force a commit in a @Transactional method?

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