Sending USSD code with alphabetic characters

android, character, character-encoding, ussd

Solution

Meaning that the dialer transform this : `#144#73MA#`

to this `#144#73``62``#` : why ?

I will try to answer only the why part.

`Intent.ACTION_CALL` is handled by `OutgoingCallBroadcaster` class. If you look at `processIntent()` method, there is this piece of code (lines 438~448 as of this writing):

String number = PhoneNumberUtils.getNumberFromIntent(intent, this);
// Check the number, don't convert for sip uri
// TODO put uriNumber under PhoneNumberUtils
if (number != null) {
    if (!PhoneNumberUtils.isUriNumber(number)) {
        number = PhoneNumberUtils.convertKeypadLettersToDigits(number);
        number = PhoneNumberUtils.stripSeparators(number);
    }
} else {
    Log.w(TAG, "The number obtained from Intent is null.");
}

There `PhoneNumberUtils.convertKeypadLettersToDigits()` converts the letters into the equivalent numeric digits:

public static String convertKeypadLettersToDigits (String input)

Translates any alphabetic letters (i.e. [A-Za-z]) in the specified phone number into the equivalent numeric digits, according to the phone keypad letter mapping described in ITU E.161 and ISO/IEC 9995-8.

Returns the input string, with alpha letters converted to numeric digits using the phone keypad letter mapping. For example, an input of "1-800-GOOG-411" will return "1-800-4664-411".

Hope this helps.

Problem

In my android app, I am sending `USSD` codes (`#144#73#`) using below `Intent` : ``` String baseUssd = Uri.encode("#") + "144" + Uri.encode("#"); StringBuilder builder = new StringBuilder(); builder.append(baseUssd); builder.append("73"); builder.append(Uri.encode("#")); Intent intent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:" + builder.toString())); ``` It's working well. What I want now is to send this code : `#144#73MA#` I run this using the dial pad, following the Operator USSD menu, that worked. But if I try to do this programmatically using the above `Intent` that didn't work. I know that alphabetic characters can't be used when typing code with the Dial Pad, but I though that It can be possible programmatically !! Any Idea please ! Edit When I try to send this programmatically : `#144#73MA#` I noticed that the Dialer application changes the alphabetic characters to their corresponding digit in the dial pad. Meaning that the dialer transform this : `#144#73MA#` to this `#144#73``62``#` : why ? Because : - the `M` matches the digit `6` - the `A` matches the digit `2`

Original source