@PostMapping("/customer")
public Customer postCustomer(@RequestBody Customer customer) {

    User user= new  User(customer.getUser().getUserName(),
customer.getUser().getPassword()
 ,customer.getUser().getEmail());

    Customer _customer = new Customer();
    User _user = new User();

    _customer.setUser(_user);
    _user.setCustomer(_customer);

     _user = usuarioRepository.save(new User(user.getUserName(),user.getPassword(),user.getEmail()));

    _customer = customerRepository.save(new Customer(customer.getName(),customer.getAge()));

    return _customer;
}

@Entity
@Table(name="user")
public class User {

@Id
@GeneratedValue(strategy= GenerationType.AUTO)
private long id;

@Column(name="userName")
private String userName;

@Column(name="email")
private String email;

@Column(name="password")
private String password;

@Column(name="logged")
private boolean logged;

@OneToOne
@JoinColumn(name = "customer_id")
private Customer customer;


public User() {

}

public User(String userName,String password,String email) {
    this.userName=userName;
    this.password=password;
    this.email=email;

}

@Entity
@Table(name = "customer")
public class Customer {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;

@Column(name = "name")
private String name;

@Column(name = "age")
private int age;

 @OneToOne(mappedBy = "customer")
private User user;

public Customer() {
}


public Customer(String name, int age) {
    this.name = name;
    this.age = age;


}