Management Domains: Asset and Dataset specialization pt. 2

[paullatzelsperger]

Feature Request

Part 2 of the implementation work for Management Domains involves the following items:

• let Catalog extend Dataset
• DatasetResolverImpl: when it encounters an Asset that is a catalog (isCatalog() method), it creates a Catalog object (instead of a Dataset) containing the URL of the linked asset in its service property
• if the JsonObjectFromDatasetTransformer encounters a Dataset, that is a Catalog, it delegates its serialization down to the JsonObjectFromCatalogTransformer

Which Areas Would Be Affected?

Dataset, Catalog, DatasetResolverImpl and their transformers

Why Is the Feature Desired?

to enable the implementation Management Domains, in particular linked catalogs

Solution Proposal

• as part of this issue, the Dataset#distributions list should be initialized with an empty Hashmap to avoid NPEs.