As we have technologies like JCA,webservices and JMS to interact b/w two applications,what is the need for Remote EJB calls or CORBA technologies. [ November 07, 2005: Message edited by: raj joe ]
Mainly because EJBs & CORBA provide middleware services, something that other technologies don�t even dare to dream of. However the point I�d like to stress is that most of the people perceive EJB as just another RMI based technology. EJBs however are broadly used without the need of making remote calls, using local interfaces only. The dilemma in my opinion started with the fact that initially EJBs were architected to be only remote components, deployed remotely probably on their own box, truly separating the BO from other application�s layers (like Microsoft DCOM technology; it is very clear � and always was, for MS developers that DCOM components are always running remotely and not locally). Unfortunately the EJB literature didn�t make clear this fact for EJB1.0. EJB2.0 on the other hand, even complicated the matter introducing the local interfaces; overnight EJBs become the solution to every business problem. However people intuition function pretty well and they are still perceived as remote components :-)
Mainly because EJBs & CORBA provide middleware services, something that other technologies don’t even dare to dream of. However the point I’d like to stress is that most of the people perceive EJB as just another RMI based technology. EJBs however are broadly used without the need of making remote calls, using local interfaces only. The dilemma in my opinion started with the fact that initially EJBs were architected to be only remote components, deployed remotely probably on their own box, truly separating the BO from other application’s layers (like Microsoft DCOM technology; it is very clear – and always was, for MS developers that DCOM components are always running remotely and not locally). Unfortunately the EJB literature didn’t make clear this fact for EJB1.0. EJB2.0 on the other hand, even complicated the matter introducing the local interfaces; overnight EJBs become the solution to every business problem. However people intuition function pretty well and they are still perceived as remote components :-)
Valentin
Thanks for info. What i exactly what to understand is when do i go for JCA or Webservice or JMS or Can i have a scenerio wherein i can use all the three.
Raj
With a little knowledge, a cast iron skillet is non-stick and lasts a lifetime.