EJB Training: Introduction to Enterprise Java Beans

nTier's EJB training course offers the Java programmers a grounding in the Enterprise JavaBeans (EJB) architecture and the skills to develop simple EJB applications. EJB's position at the heart of the Java Enterprise platform and the use of EJB application servers as the backbone of large- scale distributed systems are studied. We consider the advantages of the application server architecture – transaction control, security, persistence, scalability through pooling and clustering – and study the development process for entity and session beans in depth. The J2EE 1.4 reference implementation is used for all demo and lab work, and we emphasize portable EJB 2.1 code. The focus for this course is on end-to-end connectivity.

The course follows a path roughly from the data layer to the presentation layer, so we look at entity beans first, and work demos and exercises in both Bean-Managed and Container-Managed Persistent Beans. Then the EJB session layer is considered, and both stateless and stateful session beans are developed. As part of the lab work, these are hooked to provided JSPs to illustrate the complete system and typical architecture.

NOTE: Our JSP and Servlets courses are excellent companions to this course, and in fact the primary lab track for this course is an extension of the JSP module's labs.

• Understand the role of Enterprise JavaBeans in enterprise-level systems development, and its relationship to other J2EE technologies such as JSP, servlets, JMS, CORBA, and XML.
• Understand the EJB architecture: the role of the EJB container in mediating contact between the client and the bean, transaction control, authorization control, and the importance of object pooling.
• Understand the development cycle for EJBs: Java source code and compilation,
  XML deployment descriptors, EJB compilation and deployment, and use by an
  application server.
• Understand the role of entity beans, their lifecycle and interactions with the container.
• Develop and test BMP and CMP entity beans and understand the importance of each of the entity-bean methods in assisting the container in pooling.
• Understand the role of session beans, their lifecycle and interactions with the
  container.
• Develop and test stateless and stateful session beans and effectively manage
  passivation/activation ycles.
• Use the bean context interfaces to assist with persistence code and to correctly
  establish bean-to-bean communication.

• Solid Java programming experience is a must. Our Java Programming course is good preparation for this module.
• Some experience with distributed systems development, especially object-based systems such as Java RMI, CORBA, or COM is a plus.
• Some knowledge of JDBC is helpful in understanding the EJB persistence model. Understanding of XML is a plus but is not needed.

1. The EJB Architecture
   • EJB and the Java Enterprise Platform
   • EJB and CORBA
   • EJB Costs and Benefits
   • What is an EJB?
   • Entity, Session, and Message-Driven Beans
   • EJB Roles
   • The EJB Container
   • The Home and EJB Objects
   • EJB Development
   • Remote Interface
   • Home Interface
   • Bean Class
   • Remote, Local, and Web-Service Component Interfaces
   • Multiple Maintenance Points
   • Using JNDI in EJB
2. Entity Beans: Bean-Managed Persistence
   • Persistence Mechanism
   • Instance versus Incarnation – Similarities to the CORBA PSS
   • EntityBean Interface and Responsibilities
   • Entity Bean Interactions, Lifecycle and State Transitions
   • Primary Keys
   • EntityContext Interface and Discovering the Primary Key
   • Creation and Removal
   • Load and Store
   • Finder Methods
   • Eager vs. Lazy Persistence
3. Entity Beans: Container-Managed Persistence
   • Two Contracts for Persistence
   • Declaring a Data Source
   • Declaring Persistent Fields
   • Implementing Finder Methods
   • What the Container Does
   • 1.1 Architecture
   • 2.0 Architecture
   • CMP Limitations
4. Stateless Session Beans
   • Session Beans and the Presentation Layer
   • Stateful vs. Stateless Sessions
   • Stateful Session Bean Interactions, Lifecycle and State Transitions
   • Stateless Session Bean Interactions, Lifecycle and State Transitions
   • Finding Entity Beans
   • Passing Value Objects
5. Stateful Session Beans
   • Stateful Session Beans
   • Object Pooling and Passivation/Activation
   • Activation and Passivation
   • Choosing Between Stateful and Stateless