[FIXED] Cannot catch DataIntegrityViolationException

Issue

I am using Spring Boot 2 with spring-boot-starter-data-jpa with an underlying MariaDB.

I have table with a unique key "username". I want to catch DataIntegrityViolationException if this constraint is violated, but it seems like Spring is logging DataIntegrityViolationException and does not rethrow the after logging(my best guess). MySQLIntegrityConstraintViolationException is thrown instead.

I would like to catch DataIntegrityViolationException in UserService.createUser(..).

Here are a couple of code snippets:

@Repository
@Transactional(propagation = Propagation.MANDATORY)
public class UserRepository {

    @PersistenceContext
    private EntityManager entityManager;

    public void save(User user) {
        entityManager.persist(user);
    }
}

@Service
@Transactional(value = Transactional.TxType.REQUIRED)
public class UserService {

@Autowired
private UserRepository userRepository;

private void createUser(User user){
    userRepository.save(user);
}

Stacktrace:

2018-09-22 14:20:33.163  WARN 10700 --- [nio-8080-exec-1] o.h.engine.jdbc.spi.SqlExceptionHelper   : SQL Error: 1062, SQLState: 23000
2018-09-22 14:20:33.163 ERROR 10700 --- [nio-8080-exec-1] o.h.engine.jdbc.spi.SqlExceptionHelper   : Duplicate entry 'kkflf' for key 'user_username_uindex'
2018-09-22 14:20:33.163 ERROR 10700 --- [nio-8080-exec-1] o.h.i.ExceptionMapperStandardImpl        : HHH000346: Error during managed flush [org.hibernate.exception.ConstraintViolationException: could not execute statement]
2018-09-22 14:20:33.177 ERROR 10700 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.dao.DataIntegrityViolationException: could not execute statement; SQL [n/a]; constraint [user_username_uindex]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement] with root cause

com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'kkflf' for key 'user_username_uindex'
...

Solution

I solved the problem.

The exception does not occur until the transaction commits, which makes perfect sense.

I was able to catch the exception outside the transaction scope in a controller class.

Answered By - kkflf
Answer Checked By - Candace Johnson (JavaFixing Volunteer)