Android: detecting the current caller

@Override
public void onReceive(Context context, Intent intent) {

    TelephonyManager telephony = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
    PhoneCallStateListener customPhoneListener = new PhoneCallStateListener(context);
    telephony.listen(customPhoneListener, PhoneStateListener.LISTEN_CALL_STATE);
    helper = new ContactDatabaseHelper(context);
    list = helper.getAllContacts();

    try{
        incomingNumber = intent.getStringExtra(TelephonyManager.EXTRA_INCOMING_NUMBER);

        if (list.size() != 0){
            for ( int i  = 0, size = list.size(); i < size; i++ ){
                if (PhoneNumberUtils.compare(incomingNumber, list.get(i).getContactNumber())){                  
                    ToastMsg.showToast(context,list.get(i).getContactName()+" Calling");
                }
            }
        }


    }catch (Exception e) {
        // TODO: handle exception
    }   

}


public class PhoneCallStateListener extends PhoneStateListener{
private Context context;

public PhoneCallStateListener(Context context){
    this.context = context;
}

@Override
public void onCallStateChanged(int state, String incomingNumber) {  

    switch (state) {

        case TelephonyManager.CALL_STATE_RINGING:       


            break;
        case PhoneStateListener.LISTEN_CALL_STATE:

    }
    super.onCallStateChanged(state, incomingNumber);
}
}

Credit Naser Shaikh