In this section we modify our object model and make it bidirectional. We will also take the opportunity to override some mapping defaults. Shown below is a UML diagram for the bidirectional model.

A Customer entity can now be referenced by Account and Address entities. However, we still leave the Customer and Referee relationship unidirectional; we have no need in our application to reference a Customer entity from a Referee entity.

@Entity
public class Customer implements Serializable {
private int id;
private String firstName;
private String lastName;
private Referee referee;
private Collection<Address> addresses;
private Collection<Account> accounts;
public Customer() {}
@Id
@Column(name="CUSTOMER_ID")
public int getId() { return id; }
public void setId(int id) { this.id = id; }
@Column...