Question

The documentation says that the ValidatorFactory is thread-safe, but I have a concern about using the annotated service “InvService” as shown below, as a class property.

I am wondering if this approach is thread-safe? I basically need to do a database lookup based on the constraint violation.

public class MyValidator {

    @Autowired
    InvService invService;                        //  ??????
    private final ValidatorFactory factory;


    public MyValidator() {
        factory = Validation.buildDefaultValidatorFactory();
    }


    public <T> void validate(final T instance) {
        final Validator validator = factory.getValidator();


        final Set<ConstraintViolation< T>> violations = validator.validate(instance, Default.class);

        if (!violations.isEmpty()) {
            final Set<ConstraintViolation<?>> constraints = new HashSet<ConstraintViolation<?>>(violations.size());

            for (final ConstraintViolation<?> violation : violations) {
                constraints.add(violation);
            }
            getDBRecords(constraints); 
            throw new ConstraintViolationException(constraints);
        }
    }

    private getDBRecords(Set<ConstraintViolation<?>> constraints) {
        invService.get(....);
    }
}

This is what the service class looks like:

@Service
public class InvServiceImpl implements InvService {

    @Autowired
    private InvDAO InvDAO;
    private final Logger log = LoggerFactory.getLogger(this.getClass());


    @Override
    public <T extends InvContent>  getProduct(String InvKey) {
        return InvDAO.getInvContent(InvKey, TYPEPROD, Product.class);
    }
}

Answer 1

That depends… is InvService thread-safe? If it is, then you are OK. Thread-safe classes may reference instances of other thread-safe classes as attributes and remain thread-safe themselves. But you have to be sure that the object you are referencing is thread safe. If you did not develop the class, I would want to see documentation that explicitly says it is thread-safe.