Java Persistence with Hibernate

6.2. Collections of components

You could map Image as an entity class and create a one-to-many relationship from Item to Image. However, this isn't necessary, because Image can be modeled as a value type: Instances of this class have a dependent lifecycle, don't need their own identity, and don't have to support shared references.

As a value type, the Image class defines the properties name, filename, sizeX, and sizeY. It has a single association with its owner, the Item entity class, as shown in figure 6.5.

As you can see from the composition association style (the black diamond), Image is a component of Item, and Item is the entity that is responsible for the lifecycle of Image instances. The multiplicity of the association further declares ...