Persistence, Customizers - Java Beans

Persistence

Persistence is the ability to save the current state of a Bean, including the values of a Bean’s properties and instance variables, to nonvolatile storage and to retrieve them at a later time. The object serialization capabilities provided by the Java class libraries are used to provide persistence for Beans.

The easiest way to serialize a Bean is to have it implement the java.io.Serializable interface, which is simply a marker interface. Implementing java.io.Serializable makes serialization automatic. Your Bean need take no other action. Automatic serialization can also be inherited. Therefore, if any superclass of a Bean implements java.io.Serializable, then automatic serialization is obtained.

When using automatic serialization, you can selectively prevent a field from being saved through the use of the transient keyword. Thus, data members of a Bean specified as transient will not be serialized.

If a Bean does not implement java.io.Serializable, you must provide serialization yourself, such as by implementing java.io.Externalizable. Otherwise, containers cannot save the configuration of your component.

Customizers

A Bean developer can provide a customizer that helps another developer configure the Bean. A customizer can provide a step-by-step guide through the process that must be followed to use the component in a specific context. Online documentation can also be provided. A Bean developer has great flexibility to develop a customizer that can differentiate his or her product in the marketplace.