JPA: Override a property attribute in a subclass

[xcallejas]

Hi,

I have a subclass of a JPA entity, superclass that I cannot modify, but I
need to mark some fields (in the subclass) with:

@Column(updatable = false, insertable = false)

because I need to use another property in the subclass that manage this
field, but I cannot modify the superclass to make it to add
@MappedSuperclass.

I have tried adding @AttributeOverride annotation in the subclass like this:

@AttributeOverride(name = "paisDespacho", column = @Column(name =
"PaisDespacho", updatable = false, insertable = false))

But it seems that do nothing, when I run the application the exception says:

...
Exception [EclipseLink-48] (Eclipse Persistence Services - 1.0.1 (Build 20080905)): org.eclipse.persistence.exceptions.DescriptorException
Exception Description: Multiple writable mappings exist for the field [FASTTRACK2.Despachos.PaisDespacho].  Only one may be defined as writable, all others must be specified read-only.
...


"PaisDespacho" is a field with a propery named "paisDespacho" in the
superclass with type "String", but in the subclass I need to create a new
property that manage this field with type "Paises" (mappet to another
entity).

I cannot have access to modify the superclass.

Please help.

Thanks.

xavier.

[James Sutherland]

The JPA spec seems to indicate that AttributeOverride only applies to MappedSuperclass and Embedded, is your superclass an Entity?  You could log a bug/enhancement request to have AttributeOverride apply to inheritance as well, but still I'm not sure the updatable/insertable could be overridden.

You could try to fix up the descriptor in code using a DescriptorCustomizer.  You could add a new mapping to the ClassDescriptor for the paisDespacho and mark it readOnly.  You could also remove the ClassDescriptor's InheritancePolicy and map the inherited attributes as you wish.

xcallejas wrote:

Hi,

I have a subclass of a JPA entity, superclass that I cannot modify, but I
need to mark some fields (in the subclass) with:

@Column(updatable = false, insertable = false)

because I need to use another property in the subclass that manage this
field, but I cannot modify the superclass to make it to add
@MappedSuperclass.

I have tried adding @AttributeOverride annotation in the subclass like this:

@AttributeOverride(name = "paisDespacho", column = @Column(name =
"PaisDespacho", updatable = false, insertable = false))

But it seems that do nothing, when I run the application the exception says:

...
Exception [EclipseLink-48] (Eclipse Persistence Services - 1.0.1 (Build 20080905)): org.eclipse.persistence.exceptions.DescriptorException
Exception Description: Multiple writable mappings exist for the field [FASTTRACK2.Despachos.PaisDespacho].  Only one may be defined as writable, all others must be specified read-only.
...


"PaisDespacho" is a field with a propery named "paisDespacho" in the
superclass with type "String", but in the subclass I need to create a new
property that manage this field with type "Paises" (mappet to another
entity).

I cannot have access to modify the superclass.

Please help.

Thanks.

xavier.