gistfile1.txt

    public static Uri convertToRingtoneUri(Context context, String customRingtone) {
        if (TextUtils.isEmpty(customRingtone) || SILENT_RINGTONE_LABEL.equals(customRingtone)) {
            return null;
        }

        //Query internal media.
        ContentResolver cr = context.getContentResolver();
        Cursor c = cr.query(Media.INTERNAL_CONTENT_URI, 
                new String[]{Media._ID},
                Media.DATA + " = ?",
                new String[]{customRingtone},
                null);
        
        Uri uri = null;
        if (c != null) {
            if (c.moveToFirst()) {
                long id = c.getLong(0);
                uri = ContentUris.withAppendedId(Media.INTERNAL_CONTENT_URI, id);
            }
            c.close();
        }

        //Query external media.
        if (uri == null) {
            c = cr.query(Media.EXTERNAL_CONTENT_URI, 
                    new String[]{Media._ID},
                    Media.DATA + " = ?",
                    new String[]{customRingtone},
                    null);

            if (c != null) {
                if (c.moveToFirst()) {
                    long id = c.getLong(0);
                    uri = ContentUris.withAppendedId(Media.EXTERNAL_CONTENT_URI, id);
                }
                c.close();
            }
        }

        if (uri != null) {
            return uri;
        } else {
            return null;
        }
    }