Jakarta EE and Modern Enterprise Bean Architecture

This course Jakarta Enterprise Beans Architecture and Session Beans—is the first in the Enterprise Component Series. It introduces the evolution of Enterprise JavaBeans (EJB) from its origins in J2EE to the modern Jakarta EE ecosystem. The course explores key architectural concepts, how session beans operate within a container-managed environment, and how developers today integrate EJBs with modern Java technologies such as ExecutorService, CompletableFuture, and virtual threads.

Course Overview

Originally part of the classic J2EE platform, Enterprise JavaBeans were designed to simplify the development of distributed, transactional, and secure applications. Today, under Jakarta EE 10 and beyond, Enterprise Beans are more lightweight and integrated with modern Java features. This course focuses on two main areas:

1. The architecture of Enterprise Beans (including dependency injection and managed lifecycles)
2. Session Beans (stateless, stateful, and singleton)

In addition to learning the technology, you’ll complete a hands-on project that involves building:

• A Session Bean client using Jakarta EE APIs
• Multiple remote Session Beans that interact with shared business logic

This exercise reinforces your understanding of modular design, dependency injection, and transaction management across distributed services.

From J2EE to Jakarta EE 10 and Beyond

The Enterprise Java platform has evolved significantly since its early days:

• J2EE (Java 2 Platform, Enterprise Edition) – Introduced in 1999, it established the foundation for enterprise-scale Java applications, including EJBs, Servlets, and JSP.
• Java EE (Java Platform, Enterprise Edition) – Rebranded in 2006 with Java 5, Java EE introduced annotations, dependency injection, and modernized APIs, simplifying deployment and configuration.
• Jakarta EE (Eclipse Foundation) – Transferred to the Eclipse Foundation in 2017, this version removed the javax namespace in favor of jakarta. The latest release, Jakarta EE 10 (September 2022), introduces modular microservice-friendly APIs and aligns with Java SE 17 and beyond.

Modern Jakarta EE runtimes, such as Payara, WildFly, Open Liberty, and GlassFish—support asynchronous task execution via ManagedExecutorService and integrate seamlessly with Java SE’s ExecutorService and virtual threads introduced in Java 21. These technologies allow scalable concurrency without the complexity of manual thread management once required in earlier J2EE servers.

Payara Server is an open-source application server built on GlassFish, renowned for its support of Java EE (Jakarta EE) standards and high availability features tailored for enterprise deployments. It offers innovative technologies like Payara Micro for lightweight, cloud-native microservices and Payara Cloud for seamless Kubernetes management, ensuring scalability and resilience in modern environments. Widely adopted for its robust clustering, automatic failover, and extensive monitoring tools, Payara empowers developers to build reliable, production-ready applications with minimal configuration overhead.

Jakarta EE and Modern Java Integration

Contemporary Jakarta EE applications combine EJBs with modern Java features:

• Try-with-resources simplifies resource cleanup for database and I/O operations.
• java.time replaces legacy java.util.Date for precise, thread-safe date/time handling.
• NIO.2 (JSR 203) provides non-blocking I/O for faster file and network access.
• Virtual threads (Project Loom, Java 21) enable high concurrency without blocking threads.
• Jakarta CDI (Contexts and Dependency Injection) promotes loose coupling and dependency management, reducing reliance on manual lookup of EJB components.

These improvements ensure that Jakarta EE applications are cloud-ready, resilient, and easier to maintain, bridging traditional enterprise development with modern reactive and microservice paradigms.

Course Goals

After completing this course, you will be able to:

1. Describe the architecture and purpose of Jakarta Enterprise Beans.
2. Develop, deploy, and test Session Beans using Jakarta EE 10 or later.
3. Use dependency injection to connect EJBs with CDI-managed components.
4. Leverage asynchronous execution and virtual threads for concurrent EJB processing.
5. Combine multiple Session Beans to create modular, service-oriented applications.

Learning Methodology

You will learn and practice Jakarta EE development using modern tools and interactive examples. The course combines conceptual understanding with hands-on exercises using Jakarta EE runtimes such as GlassFish or Open Liberty. This lesson serves as the foundation for the follow-up course, Jakarta Enterprise Beans: Transactions and Persistence.