android 将手机号中间隐藏为星号（*）

if(!TextUtils.isEmpty(pNumber) && pNumber.length() >  ){
            StringBuilder sb  =new StringBuilder();
            for (int i = ; i < pNumber.length(); i++) {
                char c = pNumber.charAt(i);
                if (i >=  && i <= ) {
                    sb.append('*');
                } else {
                    sb.append(c);
                }
            }

            mPhoneNumber.setText(sb.toString());
        }