Introduction to EJB 3.0 (3 days)

Introduction to EJB Course Overview

This course introduces the experienced Java developer to Enterprise JavaBeans -- the Java EE standard for scalable, secure, and transactional Java components. EJB 3.0 has reinvigorated this area of Java enterprise development, with dramatic improvements in ease of use and smooth integration with servlet-based or JSF web applications. This course treats the 3.0 specification, with a few notes on 2.1 compatibility but an emphasis on doing things the 3.0 way.

Students get an overview of the EJB rationale and architecture, and then dive right into creating session beans and entities. The new dependency-injection features of EJB3 cause perhaps the most confusion, so we work through a chapter devoted explicitly to DI and JNDI, and basically how components find each other to make an application. We then study entities and the Java Persistence API more deeply, and get a look at message-driven beans as well.

A bridge module is also available that illustrates how JavaServer Faces (JSF) web applications can work with EJBs and Java Persistence API entities; this brief presentation can easily be added to the end of the class and works especially well to cap off a week of training using this course and our JSF course.

Introduction to EJB Course Goals

• Understand the role of EJB in the broader Java EE platform.
• Describe the features that are implemented by an EJB container on behalf of application components.
• Build stateless session beans as part of a service layer or SOA.
• Build JPA entities to represent persistent data records within the Java application.
• Develop systems of entities to manage complex data models including 1:1, 1:N, and N:N associations.
• Manage transactional behavior of the application through declarative and programmatic techniques.
• Invoke EJB sessions from Java web applications.
• Use dependency injection and JNDI names to assemble complex web/EJB systems with minimal fuss and maximal flexibility.
• Implement message-driven beans to process queued messages asynchronously.

Introduction to EJB Course Prerequisites

Experience in the following areas is required:

• Solid Java programming skills and understanding of OO Java and Java-5.0 language features is essential.
• Experience with developing Java web applications is very helpful for this course, but not strictly required.
• Some knowledge of XML will be useful for writing the occasional deployment descriptor, but is not required.

Introduction to EJB Course Outline

1. Overview
   1. Enterprise Applications
   2. Containers and Objects
   3. Three Containers
   4. Remote Connectivity
   5. Scalability and Availability
   6. Security
   7. Transaction Control
2. Architecture
   1. What is an EJB?
   2. Types of Beans
   3. Inversion of Control
   4. The Bean-Type Annotations
   5. Dependency Injection
   6. The @EJB Annotation
   7. Development Cycle and Roles
3. Session Beans
   1. Interface/Implementation Split
   2. Stateful vs. Stateless
   3. The @Stateless Annotation
   4. Lifecycle and State Transitions
   5. Session Context
   6. The @Stateful Annotation
   7. State Transitions
   8. Singletons and Pools
4. Entities
   1. The Java Persistence API
   2. Persistence Annotations
   3. Configuration by Exception
   4. ORM Annotations
   5. The EntityManager
   6. Acquiring and Using the EntityManager
   7. persistence.xml
   8. @Enumerated and @Temporal Types
5. Associations
   1. Associations, Cardinality, and Ownership
   2. Annotations
   3. Unidirectional vs. Bidirectional
   4. The @Embedded Annotation
6. Java Persistence Query Language
   1. OO Query Languages
   2. The FROM Clause and Directionality
   3. The WHERE Clause
   4. The SELECT Clause
   5. Joins
   6. Aggregates and Grouping
   7. Ordering
7. Dependency Injection
   1. Interdependent Systems
   2. The Factory Pattern
   3. The Service Locator Pattern
   4. Dependency Injection
   5. Injection by Magic?
   6. Injection by Type
   7. Injection by Name
   8. The Component Environment
   9. Deployment Descriptors
   10. Impact on Stateful Session Beans
   11. JNDI
   12. Connecting to a Remote Bean
   13. Using mappedName
   14. Who Can Declare Dependencies
8. Message-Driven Beans (Optional)
   1. Asynchronous Messaging
   2. The Java Message Service
   3. Message-Driven Beans
   4. Message Types
   5. Injecting JMS Queues

Introduction to EJB Course Materials

Each student will receive a comprehensive set of materials, including course notes and all the programming examples.

Introduction to EJB Course Technical Requirements and Setup Instructions

Click here for technical requirements and setup instructions