Hook: Define CatalogItem

Requirement

A new type of CatalogItem is needed to represent a class of objects available.

Method of Adaptation

Add Feature

Level of Support

Open Ended

HotSpot

Data management

Participants

CatalogItemImpl, NewCatalogItem

Changes

1. subclass NewCatalogItem of CatalogItemImpl.
2. NewCatalogItem.getShallowClone implements CatalogItemImpl.getShallowClone returning a normal clone of the CatalogItem.
3. if natural order is not natural order of values:
1. NewCatalogItem.compareTo overrides CatalogItemImpl.compareTo .
4. if two NewCatalogItems can be equal although they are not identical:
1. NewCatalogItem.equals overrides CatalogItemImpl.equals .
5. add new attributes as necessary.
6. add new methods as necessary.

Constraints

• Despite the name, getShallowClone must return a complete clone for all items other than actual Catalogs.
• This hook describes only the changes necessary if you use the Pure Java implementation of the data management classes.

Comments

• Usually you will need a new type of CatalogItem for every type of Catalog that your application uses. The new type is needed so that any information relevant to this class of objects can be stored appropriately and efficiently.