This was originally attached to an old post which was superficially the same question. Pradeep, could you now provide some details of your problem (instead of relying on the details of somebody else's problem)?
Well I checked the source code of JAXB. The unmarshaller class has it's own contenthandler and overrides the one passed by me always. So the conclusion is that we cannot pass our custom content handler and also error handler. Sorry bartender for the trouble caused.