itech9

• — Type of Enterprise Beans Session, Entity and Message (-Driven)
• — A session bean represents a single client inside the Application Server .
• –>> 2 types of session beans: stateless and stateful .
• –>> A stateless session bean (SLSB) does not maintain a conversational state for the client.
• –>> In a stateful session bean (SFSB), the instance variables represent the state of a unique client-bean session.
• — An entity bean represents a business object in a persistent storage mechanism.
• –>> Entity beans are persistent, allow shared access, have primary keys, and can participate in relationships with other entity beans.
• –>> Two types of persistence for entity beans: bean-managed persistence (BMP) and container-managed persistence (CMP).
• –>> Part of an entity bean’s deployment descriptor, the abstract schema defines the
  bean’s persistent fields and relationships.
• –>> Persistence factors:
  –>>– persistent fields
  –>>– Relationship Fields: 1-to-1, many-to-many, etc..), bidirectional or unidirectional
• — Message-Driven beans – JMS
• — JCM = J2EE Core Model.
• — Interfaces: EJBHome, EJBObject, SessionBean,

JBoss 4 EJBs – http://docs.jboss.org/jbossas/guides/j2eeguide/r2/en/html/ch5.chapter.html

Remote:
extends EJBObject
extends EJBHome

Local:
extends EJBLocalObject
extends EJBLocalHome

implements javax.ejb.SessionBean

implements EntityBean