Here Below I have mentioned my code.
Declare This under Oncreate
TextView TxtDocPhone=(TextView)findViewById(R.id.TxtDocPhone);
String numbersOnly = keepNumbersOnly(Phone);
String ProviderPhone = formatNumbersAsCode(numbersOnly);
Then call it
 private String keepNumbersOnly(CharSequence s) {
        return s.toString().replaceAll("[^0-9]", ""); 
    }
    private String formatNumbersAsCode(CharSequence s) {
        int groupDigits = 0;
        String tmp = "";
        for (int i = 0; i < s.length(); ++i) {
            tmp += s.charAt(i);
            ++groupDigits;
            if (groupDigits == 3) {
                tmp += "-";
                // tmp += "";
                groupDigits = 0;
            }
        }
        return tmp;
    }
Please guide me the correct way to achieve my objective.