Can anyone give me some idea of which UI framework is currently in most demand ?
Struts, JSF, Spring MVC are the ones that come to mind. Among these I get the impression Struts is still the most widely used, and JSF is set to be the replacement for struts. Spring MVC has not been widely adopted and is not likely to be as widely used as Struts or JSF. So Struts and JSF are the frameworks most worth learning for the job market.