@JsonInclude(Include.NON_NULL)
@Entity
public class Record{
    @Id
    @GeneratedValue
    private Long id;

@OneToOne(cascade = CascadeType.ALL)
    @JoinColumn(name="user_id")
    private User user;

.....getters and setters

}

@JsonInclude(Include.NON_NULL)
@Entity
public class User {

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

    @OneToOne(cascade = CascadeType.ALL, mappedBy="user")
    private Record record;

....getters and setters
}