One major disadvantage of using EJB technology for distributed components is that the client typically must also be
Java based. Of course you could use CORBA and IIOP to accomplish this, but that introduces a significant layer of complexity unless you are already using CORBA. Another disadvantage of EJBs is that they typically aren't firewall friendly, meaning that it is difficult to invoke EJBs behind firewalls. That isn't to say that EJBs aren't a good solution for certain applications. And, in fact EJBs and web services can be used together.
What web services enable is a platform independent, language independent technology for allowing two applications to interact with each other using XML as the representation format. Because
SOAP (the represenation and invocation) standard for web services typically supports HTTP as a transport, the firewall issue isn't as much of a concern because most firewalls open port 80 (or 8080) for HTTP traffic.
Have a look at the following article from XML Journal written by a colleague. It helps show examples of how web services and J2EE can work together.
http://www.sys-con.com/xml/articleprint.cfm?id=649 Best regards,
Mark
Originally posted by kris reddy:
I understand that when components are distributed and when they need to talk to each other, EJB is employed (Considering a web scenario). Do web services act as an alternative to EJB ? Any input on this is appreciated.
Thanx