Author: techfox9

J2EE 1.4 EJBs Notes..

Thursday, October 22nd, 2009 @ 12:24 am

  • — 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 –

extends EJBObject
extends EJBHome

extends EJBLocalObject
extends EJBLocalHome

implements javax.ejb.SessionBean

implements EntityBean



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