How to apply @OneToMany on super class getter method in multiple subclasses with different target entity

问题

Stack

I'm using JPA2.0 with Eclipselink 2.6.3 and Spring 4(JTA).

Problem

I'm trying to override the class A attribute with @OneToMany mapping in class B and class C (which is similar to class B ) so that I can change the target entity to class X and Z respectively while fetching results for class B.

Class A has SINGLE_TABLE inheritance and class B & C are discriminator classes which is maintained by @classExtractor depending on some field value in class A.

Class Z has TABLE_PER_CLASS inheritance and class X & Y extends class Z with same table (just a hack for inheritance to avoid DTYPE).

Expected Result When I query on class B or Class C and fetch getZList() then I should be able to see class X and Y type objects as mentioned in targetEntity in @OneToMany mapping in class B & C

I tried overriding the getter of class A in subclasses like below but the list is always empty.

Class A

@Entity
@Table(name="TABLE_A")
@Customizer(ACustomizer.class)
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
@ClassExtractor(AExtractor.class)
@InstantiationCopyPolicy
@Cacheable
@Cache( alwaysRefresh=true,
        refreshOnlyIfNewer=true,
        expiry=300000,      
        coordinationType = CacheCoordinationType.SEND_NEW_OBJECTS_WITH_CHANGES)
public class A implements Serializable {
@Column(name="ABC")
private String abc;
@Transient
private List zlist= new ArrayList<>();

}

Class B

@Entity
public class B extends A{
//problem is here...this mappping doesn't populate super class object 
@Access(AccessType.PROPERTY)
    @OneToMany(cascade=CascadeType.ALL, mappedBy="class A", targetEntity=Z.class)
    @PrivateOwned 
    public List getZList() {
        return super.getZList();
    }
}

Class Z

@Entity
@Table(name="TABLE_Z")
@Customizer(ZCustomizer.class)
@Inheritance(strategy=InheritanceType.TABLE_PER_CLASS)
public class Z{
 //some fields 
//and @oneToOne mapped with class A
}

class X

 @Table(name="TABLE_Z")
   @Entity
    public class X extends Z{
     //some fields 

    }

来源：https://stackoverflow.com/questions/44068524/how-to-apply-onetomany-on-super-class-getter-method-in-multiple-subclasses-with

标签

eclipselink

jpa-2.0

one-to-many