Convenient method to wrap an unit of work into a transaction.

[hantsy]

The JPA adds EMF.runInTransaction/EMF.calInTransaction and EM.doInConnection, and Spring also provides TransactionTemplate and TransactionalOperator(for reactive streams API).

If possible add such a method to UserTransaction or create a new TransactionalOperator for this purpose.

T doInTransaction(Function<TransactionStatus, T>)

As developers, we do not need to call begin and commit when using it.

[tomjenkinson]

Please can I ask what the difference to something like CMT or https://jakarta.ee/specifications/transactions/2.0/apidocs/jakarta/transaction/transactional would be? Perhaps you can raise this topic on our community mailing list to potentially reach the wider Jakarta Transactions community: https://accounts.eclipse.org/mailing-list/jta-dev

[hantsy]

@Transactional can not be applied in a code block.

But the methods in EMF, EM can run something like this, https://github.com/hantsy/jakartaee11-sandbox/blob/master/hibernate/src/test/java/com/example/SampleTest.java#L75

In the Jakarta Trasanction, we could provide a general purposes API like this.

public void doSomeThing() {
   txOperator.doInTransaction(status -> {
      wrap the unit of work in a tx.
   });

   // do other work outside of transation.
}

[tomjenkinson]

Thank you for providing the example. Though I can understand the code snippet you shared, I am not sure if it is substantially different enough from something like:

@Transactional (Transactional.TxType.NOT_SUPPORTED)
public void doSomeThing() {
   myRunInTransaction();
    // do other work outside of transaction.
}

@Transactional (Transactional.TxType.REQUIRES_NEW)
public void myRunInTransaction() {
}

such that it would requiring adding a new approach for transaction demarcation?

Please can I ask you to elaborate a bit on what would make the new method better? Would it be to avoid the need for CDI here? Please can you also help to define a bit what TransactionStatus would look like? Is it similar to https://jakarta.ee/specifications/transactions/2.0/apidocs/jakarta/transaction/status or does it have some more functionality?

[hantsy]

@tomjenkinson Your code snippet can archive the purpose.

What I want here is to provide a simple programmatic approach to wrap the unit of work in a tx.

The transaction status in spring and Micronaut are similar.
Spring: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/transaction/TransactionStatus.html
Micronaut: https://micronaut-projects.github.io/micronaut-data/3.0.0/api/index.html?io/micronaut/transaction/TransactionStatus.html

[tomjenkinson]

Thank you for reviewing the snippet. I think perhaps it would be useful to introduce this topic to the jta-dev mailing list for wider feedback from our community on this feature request?