[SOLVED] Java Convert 7bit Charset Octets to Readable String (From PDU SMS)

Java Convert 7bit Charset Octets to Readable String (From PDU SMS)

I'm receiving SMS from GSM modem in PDU format; the TP-User-Data is "C8329BFD06DDDF72363904"
and what I get is: "�2��r69", while the sent sms is "Hello World!".

Here is my java code:

    private String fromPDUText(String PDUSMSText) {
    String endoding = PDUSMSText.substring(0, 2);
    PDUSMSText = PDUSMSText.substring(18);
    byte bs[] = new byte[PDUSMSText.length() / 2];
    for(int i = 0; i < PDUSMSText.length(); i += 2) {
        bs[i / 2] = (byte) Integer.parseInt(PDUSMSText.substring(i, i + 2), 16);
    }
    try {
        String out = new String(bs, "ASCII");
    } catch(UnsupportedEncodingException e) {
        e.printStackTrace();
        return "";
    } finally {
        return out;
    }
}

Solution

The input is packed in 7-bits per character, which means that every 8 bytes encode 9 characters. Constructing a parser for this format can be a fun exercise or a frustrating experience, depending on how you take it. You are probably better off using a library, and a quick Google search reveals several code examples.