EJB (Enterprise Java Beans)
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Also called Enterprise Beans.
Enterprise Java Beans are a major part of J2EE. An application's business logic resides in Enterprise Java Beans, |
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Types of EJB
Entity Beans
Entity Beans represent persistent busieness data, for example a row in a database table. They are shared between clients.
Session Beans
Session Beans implement logic that is specific to one client session. A session bean is not shared between clients.
Message-Driven Beans
The three simple requirements for a bean
Empty constructor
A bean must have zero argument constructor.
No public instance variables
No public instance variables
getSomePersistentValue(), setSomePersistentValue()
Persistent values should be accessed through calls to
get...() and set...() methods.
Booleans' values are retrieved using
isSomeBooleanValue()