How to retrieve the amount of GPRS/3G/wifi data uploaded or downloaded from a mobile in android application

I have developing an android application, I have开发者_如何学运维 easily retrieved the calllog & SMS Inbox & Sentbox. Now I have to retrieve the amount of Internet Data(in bytes) which is uploaded or downloaded. Let me know the code

Android API dont give any method by which you can get the amount of Data that has been transferred or downloaded.