循环传播新事务（使用REQUIRES_NEW）不能按预期方式进行

Question

I am not sure why the following is not working. I want new transactions to begin in a loop (propagation = REQUIRES_NEW). And every transaction should be committed before a new transaction is fired in this loop. However, only the first iteration of the loop executes and then then nothing happens.

   @Service
    @Transactional
    public class Aimpl implements A {

    @Autowired
    private B b;

    private Logger logger = LoggerFactory.getLogger(this.getClass());

      public void methodA(List<Customer> customers){
       logger.info("before loop"); //gets printed
       customers.forEach(customer -> {
         logger.info("1"); //--> this gets printed
         b.processEachCustomer(customer);
         logger.info("2"); //- this does not get printed 
         });
         logger.info("after loop"); //does not get printed
      }
    }

//-----------------Second class----------


 @Service
    @Transactional
    public class Bimpl implements B {

     @Autowired
     private MyRepository repository;

     private Logger logger = LoggerFactory.getLogger(this.getClass());

      @Transactional(propagation = Propagation.REQUIRES_NEW)
      public void processEachCustomer(Customer customer){

        //process each customer - a new transaction everytime 
       //and it should be committed independently
       repository.updateCustomerData(customer.getId());
       logger.info("3");//this does not get printed
      }
    }

This is my repository class that just issues an update query in a table for one row.

public interface MyRepository extends Repository<Customer , Long> {

    @Modifying
    @Query("UPDATE Customer c SET c.status = 1 WHERE i.id= :id")
    int setStatusById(@Param("id") Integer id);

}

What am I doing wrong here? Basically, why does only the first iteration of the loop work and the rest do not? I am trying to debug it and do not see the application stopping at the breakpoint after the first iteration.

Answer 1

方法A将使用默认范围创建事务，因为@Transactional在类级别。

Answer 2

This worked fine when I removed the annotation from the methodA() and also removed class level transactional annotation in class Aimpl.

 @Service
    public class Aimpl implements A {

    @Autowired
    private B b;

    private Logger logger = LoggerFactory.getLogger(this.getClass());

      public void methodA(List<Customer> customers){
       customers.forEach(customer -> {
         b.processEachCustomer(customer);
         });
      }
    }

//-----------------Second class----------

@Service
@Transactional
public class Bimpl implements B {

 @Autowired
 private MyRepository repository;

 private Logger logger = LoggerFactory.getLogger(this.getClass());

  @Transactional(propagation = Propagation.REQUIRES_NEW)
  public void processEachCustomer(Customer customer){

    //process each customer - a new transaction everytime 
   //and it should be committed independently
   repository.updateCustomerData(customer.getId());
  }
}

EDIT 2: Let me correct myself here. This works fine even if I do not remove transactional annotation from the method and let the class stay annotated with transactional. The real issue here was a deadlock that was happening on the database level due to lock acquired by some other process. The code is correct as it is.