JPA Enumerated annotation and EnumType.STRING

Question

Hi,
There have been a few posts about @Enumeration within JPA.
It seems that if you need to persist values other than the ordinal value
of the enumeration that there is no use in @Enumeration as a JPA
annotation.
Say I have a Enumeration called Fruit.
public enum Fruit{
APPLE,
ORANGE;
I have a fruit VARCHAR2(1) column on a table and the constraint is that the value is in ('A', 'O') corresponding to the fruits.
Firstly I annotate a field with @Enumerated(EnumType.String)
Naively I looked at the J2SE 1.5 spec and saw I couldn't override the name() method on the enumeration but rather you are told to override toString().
But Toplink Essentials doesn't use toString() to get the string value of the enumeration it uses????
Is this an area which is addressed in JPA 2.0 or have missed the solution that is available in JPA 1.0 / Toplink Essentials.
Peter.

Answer 1

Peter,
I ran into the same issue mapping TopLink's original Employee demo. We have a M->Male, F->Female object-type mapping that looked like an obvious candidate for the use of an enum. Unfortunately as you have experienced JPA does not support this.
In Oracle TopLink 11gR1 and EclipseLink we have added annotations to expose our conversion mappings. With these custom annotations I can define a converter on any entity as:
@ObjectTypeConverter(name = "gender", dataType = String.class, objectType = Gender.class, conversionValues = {
          @ConversionValue(dataValue = "M", objectValue = "Male"),
          @ConversionValue(dataValue = "F", objectValue = "Female") })Then when ever I want to use it I can simply annotate the field as:
     @Basic
     @Convert("gender")
     private Gender gender = Gender.Male;I believe these conversion mappings are also available in TopLink Essentials but you would need to configure the mapping using code in a descriptor-customizer.
Doug