@Entity
@Inheritance(strategy= InheritanceType.JOINED)
@DiscriminatorColumn(name="CompanyType", discriminatorType= DiscriminatorType.INTEGER)
public abstract class ComputerSystem {
    @Id
    @GeneratedValue(strategy= GenerationType.IDENTITY)
    private long id;

    @ManyToOne
    @JoinColumn(name = "OWNER_ID", foreignKey = @ForeignKey())
    protected Company owner = null;

    public void setOwner(Company owner) {
        this.owner = owner;
    }
}

@Entity
@DiscriminatorValue("2")
public class ManufacturerComputerSystem extends ComputerSystem {
}

@Entity
@Inheritance(strategy= InheritanceType.JOINED)
@DiscriminatorColumn(name="CompanyType", discriminatorType= DiscriminatorType.INTEGER)
public abstract class Company {
    @Id @GeneratedValue(strategy=GenerationType.IDENTITY)
    protected long id;

    @OneToMany(mappedBy="company", orphanRemoval=true, cascade=CascadeType.ALL, fetch=FetchType.LAZY)
    private List<Person> people = new ArrayList<>();

    public List<Person> getPeople() {
        return people;
    }

    public void addPerson(Person person) {
        people.add(person);
        person.setCompany(this);
    }
}

@Entity
@DiscriminatorValue("1")
public class ManufacturerCompany extends Company {
    @OneToOne(orphanRemoval=true, cascade=CascadeType.ALL, fetch=FetchType.LAZY)
    @JoinColumn(name = "COMPUTERSYSTEM_ID", foreignKey = @ForeignKey())
    private ManufacturerComputerSystem computerSystem;

    public void setComputerSystem(ManufacturerComputerSystem computerSystem) {
        this.computerSystem = computerSystem;
        computerSystem.setOwner(this);
    }
}

@Entity
public class Person {
    @Id
    @GeneratedValue(strategy= GenerationType.IDENTITY)
    private long id;

    private String firstName;

    @ManyToOne(fetch=FetchType.LAZY)
    @JoinColumn(name = "COMPANY_ID", foreignKey = @ForeignKey())
    private Company company;

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setCompany(Company company) {
        this.company = company;
    }
}

public class JPAUnitTestCase {
    @Before
    public void init() {
        // Details omitted for brevity
    }

    @Test
    public void refresh_test() {
        EntityManager entityManager = entityManagerFactory.createEntityManager();

        ManufacturerCompany manufacturerCompany = entityManager.find(ManufacturerCompany.class, 1L);
        entityManager.refresh(manufacturerCompany);
        List<Person> people = manufacturerCompany.getPeople();
        Person person1 = people.get(0);     // <-- This is where it fails.
        
        String newFirstName = "name1".equals(person1.getFirstName()) ? "name2" : "name1";
        entityManager.getTransaction().begin();
        person1.setFirstName(newFirstName);
        entityManager.getTransaction().commit();
        assertEquals("Get latest name", newFirstName, person1.getFirstName());
    }
}