We can't use the same class to map ISO 3166-1 and CGSpace country
vocabularies because our Gson is old and lacks the support for the
"alternate" value in its annotations (added in Gson 2.5). So it's
better to create multiple classes that extend the base one instead
of creating a custom deserializer. Each extended class then uses
its own Serializedname.
That's the same version that DSpace 5.8 is using so we should use
it here as well so we don't forget. Unfortunately this means that
we can't use the ability to use alternate serializednames. We will
need to create different classes to map to our different JSON files
instead of simply matching different elements on the fly.
Based on Peter's preferred display values for these countries. We
will still use their ISO 3166-1 country codes so we include their
appropriate data from the iso-codes iso_3166-1.json list.
I will use the same format as the ISO 3166-1 JSON to make parsing
easier. I will add a new "cgspace_name" key to indicate our custom
name, though the codes will map to the standard ISO 3166-1 codes.
If an item has country metadata (cg.coverage.country) and no alpha
codes we check for name matches in ISO 3166 and add alpha_2 codes.
The name matching checks for a case-insensitive match on either an
ISO 3166-1 name, official name, or common name.
Our Java class needs to match the input JSON structure exactly, but
we can't use "3166-1" as a variable name so we tell GSON to use the
name "3166-1" when deserializing to countries.