Why to use JMS when I have other messaging technologies like MQ etc.?Your question is ill-formed. JMS is not a messaging technology. It is an API for messaging technologies. If you have MQ you can use JMS as the API. If you have some other messaging technology you can still use JMS as the API. Your application code barely needs to change at all if you decide to switch from one messaging technology to another. That's what JMS is for.
kiran wrote:Of course there are no such things. Asynchronous messaging can be implemented in several ways.
what is the thing that we can achieve only with JMS?
[for example: This can only be done by none other than JMS ... anything like that?]