NullPointer exception calling from Controller to Facade?

Hello Hybris Experts,

Am getting NullPointer exception when am calling from controller to facade.

Below is the piece of code added in controller class

Integer getMdfAmount=null; final mdfBalanceData getMdfBalData= mdfBalFacade.getAvailBal(getMdfAmount); model.addAttribute("getMdfBalData", getMdfBalData);

Error from console

java.lang.NullPointerException de.hybris.platform.b2bacceleratoraddon.controllers.pages.checkout.steps.PaymentTypeCheckoutStepController.enterStep(PaymentTypeCheckoutStepController.java:96) de.hybris.platform.b2bacceleratoraddon.controllers.pages.checkout.steps.PaymentTypeCheckoutStepController$$FastClassBySpringCGLIB$$8c8f1bcc.invoke(

Appreciate your help!

Thanks in Advance,

BR R venkata karthik