Java serialization refers
to either default serialization, which uses the Serializable interface,
or custom serialization, which uses both the Serializable and Externalizable
interfaces.
Some cases exist where objects must be modified to use custom serialization, such as implementing the java.io.Externalizable interface or by implementing the writeObject and readObject methods for classes implementing the java.io.Serializable interface. Custom serialization techniques should be employed when the objects are serialized using mechanisms other than the ObjectGrid API or EntityManager API methods.
For example, when objects or entities are stored as instance data in a DataGrid API agent or the agent returns objects or entities, those objects are not transformed using an ObjectTransformer. The agent, will however, automatically use the ObjectTransformer when using EntityMixin interface. See DataGrid agents and entity based Maps for further details.