Enterprise JavaBeans (EJB) is a server-side component architecture used in Java Platform, which enables modular construction of enterprise applications based on Java.
EJB was first developed by IBM, which was later implemented by Sun Microsystems. Moreover, the later version of EJB has been developed by Java Community Process, which has developed the advanced versions of EJB like EJB 2.0, EJB 2.1, EJB 3.0, EJB 3.1 and EJB 3.2.
In this EJB tutorial you will learn the entire concept of Enterprise JavaBeans beginning from the basics to the advance concepts of EJP integrated with simple examples it make it easy to understand. Some basic concepts one should know before going in depth about EJB are:
The EJB application server is known as an EJB server, which can be a web server, mail server, print server, database or some other server. An application server accepts the connections to accept the requests and then responses back. Moreover, it can run remotely or can exist on the same computer where the client application is running.
EJB is a server-side model that manages control and provides services through a specific framework known as a container. There are basically five type of EJB Containers of which three are server-side containers and two client-side containers.
Server-side containers: This consists of the server itself providing proper environment to EJB. The other two types are EJB container, which manages the EJB components and web containers, which manages servlets and JavaServer Pages.
Client-side Containers: This consists of a container for the familiar Java applications which starts with java commands and an applet container or browser enabled with Java Plug-in.
Enterprise beans are the Java EE server side components that are installed in the EJB containers through the process of deployment and then Java Virtual Machines (JVM) at the request of a client program. Enterprise applications are the software applications, which are developed with an objective of using at a large scale. This includes huge number of data accessing by many users. Moreover, Enterprise beans perform many other tasks like interaction with clients, maintaining session for the clients retrieving and holding data from the database and communicating with the server.