Persistence

A Bean persists by having its properties, fields, and state information saved and restored to and from storage.

You can control the level of serialization that your Beans undergo:

• Automatic: implement Serializable. Everything gets serialized.
• Selectively exclude fields you do not want serialized by marking with the transient (or static modifier
• Complete control: implement Externalizable, and its two methods.

Some important points about working with the Serializable interface:

• Classes that implement Serializable must have a no-argument constructor.
• There is no need to implement Serializable in your class if it is already implemented in a superclass.
• All fields but static and transient are serialized. Use the transient modifier to specify fields you do not want serialized, and to specify classes that are not serializable.