Spring Transaction: What will happen if I don't give @Transaction annotation on method

Question

I am using Spring-Boot, Spring Rest Controller and Spring Data JPA. If I don't specify @Transaction then also record get's created but I will like to understand how it happens.My understanding is that Spring by default adds a transaction with default parameters but not sure where it adds is it add Service layer or at Repository.

 public interface CustomerRepository extends CrudRepository<Customer, Long> {

    List<Customer> findByLastName(String lastName);
 }

 @Service
 public class CustomerServiceImpl implements CustomerService> {

   List<Customer> findByLastName(String lastName){
     //read operation
    }

 // What will happen if @Transaction is missing. How record get's created without the annotation
  public Customer insert(Customer customer){
  // insert operations
   }
 }

voted because I have same question and take a long time to find the answer. — Bằng Rikimaru, Jun 08 '17 at 10:04
Imho, Spring shouldn't add any tx behavior. What you'll get with traditional RDBMS is 'auto-commit' execution mode, where each SQL statement executing in its own separate transaction. — Victor Sorokin, Feb 27 '19 at 16:31

score 6 · Accepted Answer · answered Sep 16 '16 at 20:35

Spring Data JPA adds the @Transactional annotation at the Repository layer specifically in the class SimpleJpaRepository.This is the base Repository class which is extended for all Spring Data JPA repositories

e.g

/*
     * (non-Javadoc)
     * @see org.springframework.data.repository.CrudRepository#save(java.lang.Object)
     */
    @Transactional
    public <S extends T> S save(S entity) {

        if (entityInformation.isNew(entity)) {
            em.persist(entity);
            return entity;
        } else {
            return em.merge(entity);
        }
    }

score 3 · Answer 2 · edited May 23 '17 at 12:34

3

Although Spring add automatically the @Transactional annotation at DAO layer, it is not the correct place nor correct behavior. The annotation must be located at service layer, there is an answered question here.

edited May 23 '17 at 12:34

Community

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answered Sep 16 '16 at 20:56

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Spring Transaction: What will happen if I don't give @Transaction annotation on method

2 Answers2