SpringDataJpa many-to-one gives NULL

Question

I've got problem with my entities. I've trade to make many-to-one connection between this two entities. I'm doing it like that:

User user = new User();
    user.setName("a");
    user.setLastName("b");
    Set<Adress> a = new HashSet<Adress>();
    Adress a1 = new Adress();
    Adress a2 = new Adress();
    a1.setCity("a1");
    a2.setCity("a2");
    a.add(a1);
    a.add(a2);
    user.setAdress(a);
    userProxy.save(user);

My entites:

@Entity
public class User {

@Id
@GeneratedValue(strategy = GenerationType.TABLE)
private Long id;

@NotNull
private String name;

@NotNull
private String lastName;

@OneToMany(mappedBy="user", cascade=CascadeType.ALL)
private Set<Adress> adress = new HashSet<Adress>();

public User(String name, String lastName) {
    this.name = name;
    this.lastName = lastName;
}

public User() {

}

public Set<Adress> getAdress() {
    return adress;
}

public void setAdress(Set<Adress> adress) {
    this.adress = adress;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getLastName() {
    return lastName;
}

public void setLastName(String lastName) {
    this.lastName = lastName;
}

public Long getId() {
    return id;
}
}

Second Entity

@Entity
public class Adress {
@Id
@GeneratedValue(strategy=GenerationType.TABLE)
private Long id;

private String city;

@ManyToOne
@JoinColumn(name="user_id")
private User user;

public String getCity() {
    return city;
}

public void setCity(String city) {
    this.city = city;
}

public Long getId() {
    return id;
}

}

Data in table User saves fine, but in table adress field user_id is "NULL" can anyone explain to me why is that? I've tried a lots of combinations with @ManyToOne but nothing worked for me.

For more details UserProxy:

@Service
public class UserProxyDao {

private UserDao userDao;

@Autowired
public UserProxyDao(UserDao userDao) {
    this.userDao = userDao;
}

public void save(User user) {
    userDao.save(user);
}
}

however if i put @NotNull on field user in Adress entity validation fails... I really dont know why is that

Caused by: javax.validation.ConstraintViolationException: validation failed for classes [pl.rd.j2ee.api.domain.Adress] during persist time for groups [javax.validation.groups.Default, ]

Answer 1

You should be able to do this in one action as long as you do this first.

a1.setUser(user);
a2.setUser(user);

You could always add User to your Address constructor and do it there.

public Address (User user) {
    this.user = user;
}