Block a specific number?

I want to block multiple mobile numbers from my application.

I mean, you can get a blocked cell phone number or message ... but you want it to be rejected right away, without a phone call.

Is it possible to do this from within my application? If so, please give me some samples.

 Class c = Class.forName(telephony.getClass().getName());
 Method m = c.getDeclaredMethod("getITelephony");
 m.setAccessible(true);
 telephonyService = (ITelephony) m.invoke(telephony);
 telephonyService.silenceRinger();
 telephonyService.endCall();
 } catch (Exception e) {
 e.printStackTrace();