Enforcing inclusion of fields in JPA @Entity class

Question

I have multiple classes annotated with @Entity. Half of the classes have these 3 additional fields in them: specialFieldA, specialFieldB, and specialFieldC; the other half do not.

Is there a JPA way to ensure that future classes have these 3 fields in them? I.e. if a teammate wants to make another class with specialFieldA, specialFieldB, and specialFieldC in them, is there a way to enforce having these 3 fields?

I thought of using an interface, but it didn't seem like the right strategy since you can only define methods.

I can't use an abstract class because these classes already extend a parent class.

These classes already extend other classes. Edited my question. — Grant Foster, Oct 12 '18 at 16:31
https://stackoverflow.com/questions/49045027/can-i-use-mappedsuperclass-annotation-on-an-interface — Emil Hotkowski, Oct 12 '18 at 16:41

Grant Foster · Accepted Answer · 2018-11-20T18:51:18.123

0

I ended up creating a separate class with just those special fields in it and annotated the class with @Embeddable. Then in my entity I included that new class as a field and put an @Embedded annotation on it.

edited Nov 20 '18 at 18:51

answered Nov 19 '18 at 23:01

Grant Foster

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score -1 · Answer 2 · answered Oct 12 '18 at 16:42

Make a abstract class like Special fields have the annotation @MappedSuperClass

@MappedSuperClass
public abstract class SpecialFields {
  @Column(name = "specialFieldA")
  private String specialFieldA;

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

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

All the classes furthue you want to have these fields in it extends from this class Like

@Entity
@Table(name ="sample")
public class Sample extends SpecialFields  implements Serializable{
     //All three fields are part of this class and automatically maps to date base columns with same name..
}

Now all the classes which have these three fields must extends from SpecialFields class. and other are not.

OP already has an abstract class which is parent for these classes. He/she cannot extend both abstract classes/ — lealceldeiro, Oct 12 '18 at 16:44

Enforcing inclusion of fields in JPA @Entity class

2 Answers2