When do I have to make entities serializable when using EJB3?

I use all of my entities Serializable. However I think it is okay to use without serializable.

But what are the advantages of making an entity Serializable?开发者_运维问答 When do we really have to serialize an entity / or when do not?

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From the Java EE 6 Tutorial (which is quoting JSR-317 §2.1):

Requirements for Entity Classes

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If an entity instance is passed by value as a detached object, such as through a session bean’s remote business interface, the class must implement the Serializable interface.
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