I had made numerous web applications in java..
I read a lot about web services
But don’t know how to make working example in web services?
Also, don’t have any idea about ejb,jmx,etc.
Is it necessary to put web application on some server in order to implement web services?
Depending on how you define a “web service”, it can be as simple or as complex as you like. Many REST-based web services are just normal web applications that return JSON as their response instead of HTML. At the other end of the spectrum, there are SOAP (and others) that are much more involved, but can basically be called just like any other method by the consuming application.