Completing the Stack - Stripes...and Java Web Development is Fun Again - page 237

User

1 1 1

0..* 0..* 0..*

Alias Contact Folder

1

0..*

Message

1

0..*

Attachment

Figure 12.2: The webmail application model classes

about these model classes. which the JPA calls entities. Add the @Entity
annotation on each model class:

Download email_23/src/stripesbook/model/User.java
@Entity
public class User extends ModelBase {

Entities are managed by JPA and also discovered by Stripersist. We'll
see what Stripersist does for us in the next section. Let's finish anno-
tating the model for JPA.

Each model class has a property that uniquely identifies individual
objects. The @Id annotation must be added to that property for each
entity. Rather than repeat this property in each model class, we can
use an abstract base class:

Download email_23/src/stripesbook/model/ModelBase.java

@MappedSuperclass
public abstract class ModelBase {
@Id
@GeneratedValue
private Integer id;
public Integer getId() { return id; }
public void setId(Integer id) { this .id = id; }

}