We can append the codes we will add to a List of Strings and then
actually apply them later in one addMetadata call, and update the
item with one item.update() call. This reduces identical code and
is more efficient.
Note that when testing this on a collection with thousands of items
I realized that it is really important to limit both the cache size
as well as set the database transaction model to be per object/item
or else you will crash due to Java heap issues. For example:
$ ~/dspace/bin/dspace curate -t countrycodetagger -i 10568/3 -r - -l 500 -s object
See: https://wiki.lyrasis.org/display/DSPACE/Curation+Task+Cookbook
Originally I wasn't sure if I was going to try to parse each code,
check them against the mapping, and possibly correct them, but it's
easier to just skip items with codes unless we're in "force" mode.
The DSpace curation system has task properties that can be used to
create "profiles" of sorts. For example, if you set a custom task
name in curate.cfg:
plugin.named.org.dspace.curate.CurationTask = \
org.cgiar.cgspace.ctasks.CountryCodeTagger = countrycodetagger \
org.cgiar.cgspace.ctasks.CountryCodeTagger = countrycodetagger.force
... then DSpace will look for countrycodetagger.cfg by default, and
countrycodetagger.force.cfg for the second task. We can set different
properties in each one, for example "force=true", and then operate
accordingly in the task when we check the value using taskProperty().
I will use this to force all country tags to be cleared and updated,
where by default we only tag if there are no existing country tags.
See: https://wiki.lyrasis.org/display/DSDOC5x/Curation+System
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.
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.