Recipe to remove Id annotation from Embeddable class when referenced by EmbeddedId

[evie-lau]

What's changed?

Add new recipe and tests for OpenJPA -> EclipseLink migration

Remove @Id annotation if...

• parent class is @Embeddable and
• parent class referenced by @EmbeddedId

What's your motivation?

https://wiki.eclipse.org/EclipseLink/Examples/JPA/Migration/OpenJPA/Mappings#.40EmbeddedId_and_.40Id_in_the_Same_Entity

Checklist

• I've added unit tests to cover both positive and negative cases
• I've read and applied the recipe conventions and best practices
• I've used the IntelliJ IDEA auto-formatter on affected files

[timtebeek]

Implementation looks perfect to me; great to see! I've done some very minor touch ups to the docs, code highlighting inside text blocks, and formatting. Good to merge if you ask me, but let's wait for @cjobinabo to return before we merge.

[cjobinabo]

It would be good to include the following scenarios:

• Class1 annotated with @Entity and defines a field of type Class2 annotated with @Embedded. Then Class2's definition is annotated with @Embeddable and defines a field of any type annotated with @Id
• @Embeddable is used on a sub-class where this sub-class uses @Id

[evie-lau]

Does this recipe also have to handle the @Embedded case? The rule only mentioned @EmbeddableId.
Otherwise if you meant @EmbeddableId, is the first case not the same as the first test, the one annotated with @DocumentExample?

[evie-lau]

In the second case, is Class1 still defining Class2 with @EmbeddableId?
And should the recipe be expected to run on Subclass2 which extends Class2?

[cjobinabo]

I should have been clearer about describing the sub-class test case I was looking for. Something like this was what I had in mind:

              import javax.persistence.Embeddable;
              import javax.persistence.Id;
              public class SomeClass {
                  @Embeddable
                  public class EmbeddableObject {
                      @Id
                      private int field;
                  }
              }

Without calling the super class you prevent the code the from branching any deeper.

[evie-lau]

If SomeClass also had it's own @Id annotated field, should that be left unchanged by this recipe?

[evie-lau]

Conversely, if the outer SomeClass is @Embeddable, has an @Id field, and has an inner class without @Embeddable and an inner field with @Id, should that inner field annotation be removed as well?

Although not sure if this is easily feasible. Current behavior is to remove @Id from current class and all inner classes from there.

[cjobinabo]

Thanks for making the updates