What is EJB and how it works?

What is EJB and how it works?

An EJB container is a run-time container for beans that are deployed to an application server. The container is automatically created when the application server starts up, and serves as an interface between a bean and run-time services such as: Life-cycle management. Code generation. Persistence management.

What is the use of EJB in Java?

EJB is a server-side software component that encapsulates business logic of an application. An EJB web container provides a runtime environment for web related software components, including computer security, Java servlet lifecycle management, transaction processing, and other web services.

Why is EJB bad?

The biggest complaint I have against the EJB specification is its rather heavy weight programming model, which makes it difficult to decide on the granularity of the beans. Another reason why you wouldn't want your bean to implement your Remote Interface is that the remote interface extends EJBObject.

How is EJB different from Java Beans?

The main difference between EJB and Java Beans is that the EJB is a server-side software component that encapsulates the business logic of an application while JavaBeans are classes that encapsulates multiple objects into a single object that helps to create reusable software components for Java.

What are disadvantages of EJB?

Disadvantages of EJB

• The specification of EJB is pretty complicated and large.
• It creates costly and complex solutions.
• Abundant resources are utilized and they possess a lot of artefacts.
• It takes time for development.
• Continuous revision of the specifications takes place.

How is EJB used?

EJB beans are specifically designed to implement the business logic of your application. As such they provide services that are often needed when implementing such logic, such as transactions, injecting of the entity manager (used for JPA, the Java Persistence API) and pooling of beans.

Is EJB a framework?

EJB is a specification of Java EE. Spring is a framework. It can inject anything in the container including EJB Data sources, JMS Resources, and JPA Resources. ... It supports various persistence technologies such as JDBC, Hibernate, JPA, and iBatis.

What are the advantages of EJB?

The EJB architecture provides the following benefits to the application developer: simplicity, application portability, component reusability, ability to build complex applications, separation of business logic from presentation logic, easy development of Web services, deployment in many operating environments, ...

What are the disadvantages of EJB?

Disadvantages of EJB

• The specification of EJB is pretty complicated and large.
• It creates costly and complex solutions.
• Abundant resources are utilized and they possess a lot of artefacts.
• It takes time for development.
• Continuous revision of the specifications takes place.

What is the difference between Spring and EJB?

Basic Difference Between the Two. First, the fundamental and apparent difference is that EJB is a specification, whereas Spring is an entire framework. The specification is implemented by many application servers such as GlassFish, IBM WebSphere and JBoss/WildFly.

What is the difference between EJB and Java Beans?

• Difference Between EJB and JavaBeans Definition. EJB is a Java API that allows modular construction of enterprise software. ... Requirement. Also, another important difference between EJB and JavaBeans is that the EJB requires an application server or EJB container to run EJB applications. Complexity. Moreover, EJB is complex than JavaBeans. ... Usage. ... Conclusion. ...

What are the disadvantages of EJB?

• Disadvantages of EJB Requires application server Requires only java client. For other language client, you need to go for webservice. Complex to understand and develop ejb applications.

What is the difference between EJB and RMI?

• The differences between RMI and EJB are given below: In RMI, middleware services such as security, transaction management, object pooling etc. need to be done by the java programmer. In EJB, middleware services are provided by EJB Container automatically. RMI is not a server-side component. It is not required to be deployed on the server.

What is EJB role in J2EE?

• The EJB server provides an environment that supports the execution of applications developed using Enterprise JavaBeans™ (EJB) components. It manages and coordinates the allocation of resources to the applications. Enterprise beans typically contain the business logic for a J2EE application. The EJB server must provide one or more EJB containers.