JAX-WS - Service Implementation as a POJO

I was doing some reading up on building a soap service using jax-ws as part of java 6. I read that the operations that can be invoked by a client can be defined in the SEI, or Service Endpoint Interface. These operations can be implemented by a SIB, aka "Serv开发者_运维知识库ice Implementation Bean". The part that troubles me, is that this SIB "can either be a POJO or a Stateless Session EJB" according to page 4 of this book. The same definition applies on wikipedia. However, I read that a POJO (according to wikipedia) is "an ordinary Java Object, not a special object, which does not follow any of the major Java object models, conventions, or frameworks such as EJB". Thus follows my question, how can I know that my SIB is a POJO? Additionally, what is the difference between implementing my web service operations via a POJO or a stateless session EJB?

EJB 3.0 introduced annotations that allow any POJO to become a stateless session bean. Therefore the sentence "[a SIB] can either be a POJO or a Stateless Session EJB" applies to stateless session beans pre-EJB 3.0 (such as EJB 2.1). You can now write your SIB as a POJO - that is, without extending any other class or implementing any special interface that you didn't write yourself. You will still need an EJB container, though, such as WebLogic Server, IBM WAS or jBoss if you want to use EJBs.

In my point of view the biggest advantages for a ejb over POJO distrubution capacities of ejb there is plenty features exists for ejbs like CMP.

The other part any class you writed in java is a POJO in another words if your implemantion is a java class then it is a POJO.

POJO term came out for indicating that there is no need for special class type which is a need for java EE world because there is plenty special classes in java EE.

For one of advantages of ejb over POJO you can read this documentation: http://lass.cs.umass.edu/~shenoy/courses/spring11/lectures/Lec24.pdf