J2EE stands for Java 2 Platform, Enterprise Edition. It’s a set of specifications, APIs, and technologies for building enterprise-level applications in Java. J2EE provides a robust, scalable, and component-based platform for developing distributed, multi-tiered applications. It includes various services and APIs for developing web-based, enterprise-scale applications such as servlets, JavaServer Pages (JSP), Enterprise JavaBeans (EJB), Java Message Service (JMS), Java Naming and Directory Interface (JNDI), and Java Transaction API (JTA), among others.
J2EE applications typically follow a multi-tier architecture, dividing the application logic into presentation, business, and data tiers. This architecture promotes scalability, maintainability, and reusability of components.
Key components of J2EE include:
- Servlets and JSP: Used for building dynamic web applications.
- EJB (Enterprise JavaBeans): Components for building business logic that can be deployed on a server and accessed by clients.
- JMS (Java Message Service): Provides a framework for messaging between distributed components.
- JTA (Java Transaction API): Supports distributed transactions across multiple resources.
- JNDI (Java Naming and Directory Interface): Provides naming and directory functionality for accessing remote objects.
J2EE has evolved over time, and as of my last update in January 2022, it’s known as Jakarta EE, following a transition from Oracle’s stewardship to the Eclipse Foundation. However, the fundamental concepts and technologies remain largely the same, focusing on building robust enterprise applications using Java.