Are EJBs applications like Web Services?

Is developping an EJB application is considered like a web services ?

Or the two are different ?

Or you can make EJBs like web s开发者_JS百科ervices ?

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My answer would be yes and no.

No in the sense that EJB is a programming model. This programming model contains concepts such as security, transaction demarcation, state management and persistency (stateful or stateless beans), and more. While web service is more a remoting technology, that is, a way to connect systems, which is SOAP in the case of web service. Under this perspective both are completely different topic (Web service could be compared to RMI-IIOP though).

Yes in the sense that both are usually referred as technologies to expose a service to the outside (as long as it's stateless). Under this perspective they belong to the same category. And an EJB can indeed be exposed very easily as a web service by annotating the bean accordingly.

Hope it brings some light to the distinction.

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An EJB is an object that has some useful methods, typically Business Logic, and those methods can be invoked by clients in a number of ways - one of those ways can be a Web Service interface.

In development terms it's pretty much just a matter of annotating the EJB with your chosen interfaces style.

Putting the logic in an EJB can be a good idea because you get easy control over Transactional behaviour, declarative Security and scalability from the EJB container.