J2EE (Java 2 Platform, Enterprise Edition)

J2EE (Java 2 Platform, Enterprise Edition) is a Java platform designed for the mainframe-scale computing typical of large enterprises.
J2EE includes many components of the Java 2 Platform, Standard Edition (J2SE):

• The Java Development Kit (JDK) is included as the core language package.
• Write Once Run Anywhere technology is included to ensure portability.
• Support is provided for Common Object Request Broker Architecture (CORBA), a predecessor of Enterprise JavaBeans (EJB), so that Java objects can communicate with CORBA objects both locally and over a network through its interface broker.
• Java Database Connectivity 2.0 (JDBC), the Java equivalent to Open Database Connectivity (ODBC), is included as the standard interface for Java databases.
• A security model is included to protect data both locally and in Web-based applications.

J2EE also includes a number of components added to the J2SE model, such as the following:

• Full support is included for Enterprise JavaBeans. EJB is a server-based technology for the delivery of program components in an enterprise environment. It supports the Extensible Markup Language (XML) and has enhanced deployment and security features.
• The Java servlet API (application programming interface) enhances consistency for developers without requiring a graphical user interface (GUI).
• Java Server Pages (JSP) is the Java equivalent to Microsoft's Active Server Pages (ASP) and is used for dynamic Web-enabled data access and manipulation.

The J2EE architecture consists of four major elements:

• The J2EE Application Programming Model is the standard programming model used to facilitate the development of multi-tier, thin client applications.
• The J2EE Platform includes necessary policies and APIs such as the Java servlets and Java Message Service (JMS).
• The J2EE Compatibility Test Suite ensures that J2EE products are compatible with the platform standards.
• The J2EE Reference Implementation explains J2EE capabilities and provides its operational definition.