In this article on understanding Enterprise Java Beans, I will explain the concept of Enterprise Java Beans and their role in building a Java Enterprise application.
Basically, a Java Enterprise application that uses Java EE technology is a multi-layered application case. Furthermore, enterprise-level applications must be scalable and robust. These applications often consist of several layers, with each layer performing a specific function in the application. Furthermore, we can build the various layers of an application at the enterprise level using software components. EJB (Enterprise Java Beans) technology provides us with a mechanism for developing the application using components.
What are Enterprise Java Beans (EJB)?
In fact, Enterprise Java Beans (EJB) provides us with an application architecture development architecture using reusable software components. In fact, these components are on the server and apply business logic. Also, the use of EJB in apps causes the app to be distributed in nature. Because EJBs are distributed, they can be accessed by a remote client. Because EJB components are responsible for implementing business logic rather than customer, which can be JSP or servlet, customer developers can focus on developing the logic of the presentation. Hence the use of EJB in the app supports the separation of concerns so that we can develop and maintain each part of the app individually without affecting the entire app.
Another advantage of using EJB is that we can have a thinner client that includes less functionality. Therefore, the customer can operate efficiently on smaller devices. The following illustration illustrates the EJB architecture. As you can see, the application client that may be a servlet or other bean communicates with the bean through a remote or home interface. The beans run in the EJB container provided by the application server. Basically, the EJB container is a software component that provides various services like transaction management, lifecycle management and so on.
However, EJB also has some drawbacks. For example, deploying an EJB requires an application server. Hence, it adds cost to app development. Moreover, it requires Java client only. For any other customer, we need a web service. Also, EJB has a complex architecture. Hence, it requires expertise. All these things make the app more expensive. It also increases development time.
Aside from these drawbacks, EJB is a powerful technology. Because it makes the development of large applications easier and simpler.