What is ejb used for

Thread safety is built in when you're working with session beans, but both stateless and singleton beans can be accessed concurrently by multiple clients. Developers are responsible for thread safety when implementing these types of beans.

Singleton beans offer some support for thread safety via the Lock annotation. The two options are Lock LockType. WRITE , which is the default. Another useful feature of singleton beans is the ability to schedule tasks in a simple way, using the Schedule annotation.

Listing 5 shows how to schedule a task daily at noon. At a high level, CDI offers a general-purpose component framework, while EJB stands out for its richly featured, individual components. Whereas CDI uses dependency injection to define and reference any software component, EJB components are more formally defined, with each offering a specific set of capabilities out of the box. Enterprise JavaBeans was the first specification to offer an easy way of encapsulating and re-using business logic in enterprise Java applications.

Far from the heavyweight behemoth of old, EJB today is a lean, annotations-based framework that lets you access a wide range of enterprise functionality, right out of the box. Consider EJB the next time you're asked to quickly ramp up a distributed, scalable business application. You might be pleasantly surprised. This story, "What is EJB? He believes in people-first technology. When not playing guitar, Matt explores the backcountry and the philosophical hinterlands.

He has written for JavaWorld since Here are the latest Insider stories. More Insider Sign Out. Sign In Register. Sign Out Sign In Register. Latest Insider. The EJB specification calls for two types of session bean: stateless and stateful beans. Stateful beans are useful for longer-duration sessions, in which it is necessary to maintain state, such as instance variable values or transactional state, between method invocations.

Thus, EJB activates only stateful session beans on demand in a new session. Stateful beans can offer the same performance as stateless beans, while preserving the "conversational state". This code is the business logic of the application, usually involving database access.

The EJB deployer writes the deployment descriptor files that specify the properties of each bean to be deployed. Because Oracle8i is a highly scalable server, only the essential components of the interpreter are necessary--namely, a set of Java classes that do the following: decode the IIOP protocol find or activate the relevant Java object invoke the method the IIOP message specifies write the IIOP reply back to the client Oracle8i does not use the ORB scheduling facilities.

On top of this infrastructure, Oracle8i implements the EJB programming model. Stateless beans--which do not share state or identity between method invocations--find use mainly in middle tier application servers that provide a pool of beans to process frequent and brief requests, such as those involved in an OLTP application.

All Rights Reserved. Library Solution Area Contents Index. It is a specification provided by Sun Microsystems to develop secured, robust and scalable distributed applications.

To get information about distributed applications, visit RMI Tutorial first. It performs: life cycle management, security, transaction management, and object pooling. EJB application is deployed on the server, so it is called server side component also. It encapsulates the state that can be persisted in the database. It is deprecated. If bean client need to be written in other language such as. So EJB with web service will be better option.

JavaTpoint offers too many high quality services. Mail us on [email protected] , to get more information about given services.

Please mail your requirement at [email protected] Duration: 1 week to 2 week. EJB Tutorial. Next Topic What is Session Bean. Reinforcement Learning. R Programming. React Native. Python Design Patterns. Python Pillow.