how to update an entity with spring data jpa

Question

I have an entity and a Junit, I want to test that update method is working fine, but when I invoke save method from CrudRepository I get a new entry in my table instead of the updated entity.

This is my entity:

@Entity(name = "PERSON")
public class Person {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "PERSON_ID")
    private Integer id;
    @Column(name = "FIRST_NAME")
    private String firstName;
    @Column(name = "LAST_NAME")
    private String lastName;
//getters and setters
}

This is my service class:

@Service
public class PersonServiceImpl implements PersonService {

    @Autowired
    private PersonRepository personRepository;

    @Override
    public Person updatePerson(Person oldPerson) throws Exception { 

        return personRepository.save(oldPerson);
    }
}

This is my repository

public interface PersonRepository extends CrudRepository<Person, String> {
}

This is my test:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = { JPAConfigurationTest.class })
@DirtiesContext(classMode = ClassMode.AFTER_EACH_TEST_METHOD)
@Transactional
public class UpdatePersonServiceIntegrationTest {
        @Autowired
    PersonService personService;

        @Before
    public void setUp() throws Exception {
        Person person = new Person(1);
        person.setFirstName("Nicolas");
        person.setLastName("Spessot");

        personService.createPerson(person); //This invokes save
    }

        @Test
    public void updatingPerson() throws Exception{
        Person person = new Person(1);
        person.setFirstName("Juan");
        person.setLastName("Riquelme");

        personService.updatePerson(person);

        Person retrieved = personService.retrievePerson(1); //This invokes findOne

        assertEquals(1, person.getId());
        assertEquals("Juan", person.getFirstName());
        assertEquals("Riquelme", person.getLastName());
    }
}

Thanks in advance

Answer 1

The problem is in your updatePerson method in your service class. Specifically:

return personRepository.save(oldPerson);

All you are currently doing is saving a Person. That's why it is creating a second entry.
What you should do is find the oldPerson first,

Person p = personRepository.findOne(oldPerson.getId())

then update its attributes, and then save it like you did before. Hope that helps.