What is the full form of EJB

EJB: Enterprise Java Bean

EJB stands for Enterprise Java Bean. It is a Java application programming interface (API) for Java Platform, Enterprise Edition (JEE). It is provided by Sun Microsystems to simplify the development of large, secured, and scalable distributed applications.

EJB component is a server-side and platform-independent software component that represents the business logic in scalable, multilayer, and distributed applications. Thus, it simplifies the application developer's work by allowing them to focus on their business logic.

When is EJB needed?

1. When the data and resources are distributed across various sites.
2. When the application is performance-centric, it needs to be scalable.
3. When you need to manage the transactions, the EJB container can manage your transaction boundaries.
4. When the application needs encapsulated business logic, the separation between business logic and display.

EJB Types

There are three types of EJB; session bean, entity bean, and message-driven beans.

1. Session bean: It implements the business logic of the client, e.g., it can calculate interest on deposits for a banking application.

1. Stateful Session Bean: A state is used by a stateful session bean to carry out business tasks. A stateful session bean that stores the information in an instance variable may be utilised to access different method calls. Certain applications demand that data be stored across many methods calls. In a shopping site, the things chosen by a customer must be kept as data is an example of a stateful session bean.
2. Stateless Session Bean: Stateless session beans can leverage shared data and apply business logic without a permanent storage system, such as a state or database. When information does not need to be shared between call methods, stateless session beans can be utilised.

2. Entity bean: It is a data component that persists the data in the database.

3. Message-driven bean: It manages messages asynchronously, so used in asynchronous communication scenarios like receiving JMS messages.

Enterprise Java Beans' benefits

1. Since the EJB repository provides enterprise beans with system-level services, bean developers may concentrate on finding solutions to business issues. The EJB repository, as opposed to the bean developer, is in charge of system-level functions, including transaction management and security authorisation.
2. Because the application's business logic is contained in the beans rather than the clients, the client developer may concentrate on the client's interface. The client developer is not required to write the code for the pattern that accesses databases or executes business rules. As a result, the clients are slimmer, which is a feature that is crucial for clients who operate on small devices.
3. Since Enterprise Java Beans are portable components, application assemblers may create new applications using pre-existing beans.

Enterprise Java Beans' drawbacks

1. Application server is necessary
2. It just needs a Java client. You must use a web service for clients who speak other languages.
3. EJB application development and understanding are difficult.

Advancement

Throughout time, EJB has changed to accommodate the shifting demands of corporate applications. EJB 3.2, the most recent version, was made available with Java EE 7. Many updates and new features are included in this edition, including support for asynchronous processing, increased speed, and more straightforward programming paradigms.

Summary

For creating distributed, scalable, and secure corporate applications in Java, EJB offers a strong component architecture. It offers a collection of common APIs and services that make it easier to create complex systems, and it is always developing to suit the changing demands of the organisation.