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Lucas. D
Asked: 2020-02-23 06:05:58 +0800 CST 2020-02-23 06:05:58 +0800 CST

Expression of type List needs unchecked conversion to conform to List<>

  • 772

I have a repository class that implements from another a method to get all my clients

@Repository
public class ClienteRepositoryImpl implements ClienteRepository{

    private EntityManager em;

    @Override
    @Transactional(readOnly = true)
    public List<ClienteEntity> findAll() {

        return em.createQuery("from Cliente").getResultList();

    }

}

The problem is that in the return line it throws me the following warning

Type safety: The expression of type List needs unchecked conversion to conform to List

I have searched in different places and it is not so clear to me why Java throws this at me. I have also read some questions on the subject in English, such as this one where the use of the @SuppressWarnings("unchecked") tag is even recommended, as well as disabling the warnings that cannot be avoided, something that for me is a bad practice .

How could I avoid this type of warning without the use of tags like the one mentioned?

java

1 Answers

  1. Best Answer

    You can try one TypedQuery:

    return em.createQuery("from Cliente", ClienteEntity.class).getResultList();
    • 4