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Entity ID Management

To persist entities and reference them beyond runtime, persistence identification is needed. This identification is based on ID properties.

On this page

  1. General
  2. Accessing ID Property
  3. Partition Identification
  4. Global Identification

General

When your entity extends GenericEntity, the ID property is inherited from the supertype and you do not need to explicitly mark a property if you want to use it as an ID.

Accessing ID Property

Although the ID property can be type-individual, you can access it in a normalized way using one of the following methods:

  • <T> T getId();
  • void setId(Object id);

Partition Identification

Data supply chain can combine separate data storages into a virtual data storage, in which certain types can come from either one of the separate data storages. The type com.braintribe.model.generic.GenericEntity introduces the partition property of type string to distinguish between the separate storages if needed.

Global Identification

Persistence IDs are only guaranteed to be unique within a specific storage. Also, migrating data from one storage to another leads to the necessity of id translations. For stable identification throughout those migrations, the type com.braintribe.model.generic.GenericEntity introduces the globalId property of type string to globally identify entity instances over time and across storages.

The globalId property is especially interesting for the cortex storage which frequently exchanges data for collaboration purposes (e.g. model exchange, release package updates). In case of the cortex storage, a random UUID is automatically assigned to any instance being persisted not yet having an assigned globalId. That ensures a UUID is present for all instances. Other storages may ignore the globalId property.

The cortex storage builds its persistence with incremental manipulation stacks based on globalId references in order to stabilize it for collaboration. The globalId property is generally either a random UUID or a URI with a scheme so it may come from manual assignment with semantic information (e.g. GmProperty.globalId = “property:com.braintribe.model.generic.GenericEntity/globalId”).