smspducodec.java

This serial client in JAVA allows sending, reading and writing of SMS via a serial COM port. The too

// Serial SMS Client for handling SMS communication with a mobile terminal
// (C) 2001 by Stefan Moscibroda

// This SMS encoding/decoding helping class includes software functionality
// originally developed by "Kvanttisofta oy."



import java.util.*;

public class SmsPduCodec {
    private static final char EMPTYCHAR = 0x100;
    private static final char EXTTABLEESCAPE = 0x1B;
    private static char[] gsmToIsoMap; // GSM ==> ISO88591
    private static char[] gsmToIsoExtMap;
    private static char[] isoToGsmMap; // ISO88591 ==> GSM
    private static char[] isoToGsmExtMap;

    private static char[] hexDigits = { '0', '1', '2', '3', '4', '5', '6', '7',
					'8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
    };


    // nicely display time and date of received SMS
    public static String displayTimeDate(Calendar cal)
    {
      String out="";
      int year = cal.get(Calendar.YEAR);
      int month = cal.get(Calendar.MONTH) + 1;
      int day = cal.get(Calendar.DAY_OF_MONTH);
      int hour = cal.get(Calendar.HOUR_OF_DAY);
      int minute = cal.get(Calendar.MINUTE);
      int second = cal.get(Calendar.SECOND);
      int zone = cal.get(Calendar.ZONE_OFFSET)/(60*60*1000)*4;
      String year_str =  String.valueOf(year);
      String month_str = String.valueOf(month);
      String day_str = String.valueOf(day);
      String hour_str = String.valueOf(hour);
      String minute_str = String.valueOf(minute);
      String second_str = String.valueOf(second);
      String zone_str = String.valueOf(zone);
      if (year_str.length() < 2) year_str = "0" + year_str;
      if (month_str.length() < 2) month_str ="0" + month_str;
      if (day_str.length() < 2) day_str = "0" + day_str;
      if (hour_str.length() < 2) hour_str = "0" + hour_str;
      if (minute_str.length() < 2) minute_str = "0" + minute_str;
      if (second_str.length() < 2) second_str = "0" + second_str;
      out = hour_str + ":" + minute_str + ":" + second_str + "  ";
      out = out + day_str + "-" + month_str + "-" + year_str;
      return out;
    }


    // Needed because of special time stamp coding
    // swaps characters of every two character substring of a string.
    public static String swapDigits(String str) {
	if( str == null )
	    return str;

	int strlen = str.length();
	StringBuffer sb = new StringBuffer(strlen);

	for(int i=0; (i+1) < strlen; i=i+2) {
	    sb.append(str.charAt(i+1));
	    sb.append(str.charAt(i));
	}
	return new String(sb);
    }

    // converts an 8 bit integer into a hexadecimal string
    public static String toHexString(int b) {
	char[] digits = new char[2];
	b = b & 255;

	digits[0] = hexDigits[b / 0x10];
	digits[1] = hexDigits[b % 0x10];

	return new String(digits);
    }

  
    // Conversion: 7 bit character string --> 8 bit bytes as hex string   
    public static String sevenBitEncode(String message) {
	if(message == null)
	    return message;
	StringBuffer msg = new StringBuffer(message);

	StringBuffer encmsg = new StringBuffer(2*160);
	int bb = 0, bblen = 0, i;
	char o=0, c=0, tc;

	for(i=0; i < msg.length() || bblen>=8; i++) {
	    if(i<msg.length()) {
		c = msg.charAt(i);
		tc = isoToGsmMap[c];
		/*
		  if(tc == EXTTABLEESCAPE) {
		  //msg.insert(i+1, isoToGsmExtMap[c]);
		  }
		*/
		c = tc;

		c &= ~(1 << 7); // clear (discard) eight bit.
		bb |= (c << bblen); // insert c to bb.
		bblen += 7;
	    }

	    while(bblen >= 8) { // we have a full octet.
		o = (char) (bb & 255); // take 8 bits.
		encmsg.append(SmsPduCodec.toHexString(o));
		bb >>>= 8;
		bblen -= 8;
	    }

	} // end: for(i=0; i<msglen || bblen>=8; i++) {

	if( (bblen > 0) )
	    encmsg.append(SmsPduCodec.toHexString(bb));

	return encmsg.toString();
    }

    public static String sevenBitDecode(String encmsg) {
	return sevenBitDecode(encmsg, encmsg.length());
    }

    // Conversion: 8 bit bytes as hex strings --> 7 bit characters string
    public static String sevenBitDecode(String encmsg, int msglen)
	throws NumberFormatException {
	// encmsg: encoded string to decode.
	// msglen: the requested number of characters to decode.

	int i, o, r=0, rlen=0, olen=0, charcnt=0; // ints are 32 bit long.
	StringBuffer msg = new StringBuffer(160);
	int encmsglen = encmsg.length();
	String ostr;
	boolean exttableescape = false;
	char c;

	// assumes even number of chars in octet string.
	for(i=0; ((i+1)<encmsglen) && (charcnt<msglen); i=i+2) {
	    ostr = encmsg.substring(i, i+2);
	    o = Integer.parseInt(ostr, 16);
	    olen = 8;

	    if(rlen >= 7) { // take a full char off remainder.
		c = (char) (r & 127);
		r >>>= 7;
		rlen -= 7;
		msg.append(c);
		charcnt++;
	    }

	    o <<= rlen; // push remainding bits from r to o.
	    o |= r;
	    olen += rlen;

	    c = (char) (o & 127); // get first 7 bits from o.
	    o >>>= 7;
	    olen -= 7;

	    r = o; // put remainding bits from o to r.
	    rlen = olen;

	    // handle character conversion.
	    c = gsmToIsoMap[c];

	    if( c == EXTTABLEESCAPE ) { // ext table character handling.
		exttableescape = true;
		continue;
	    } else if( exttableescape == true) {
		exttableescape = false;
		c = gsmToIsoExtMap[c];
	    }

	    msg.append(c);
	    charcnt++;
	} // end: for(i=0; ((i+1)<encmsglen) && (charcnt<msglen); i=i+2) {

	if( (rlen>0) && (charcnt<msglen) )
	    msg.append((char)r);

	return msg.toString();
    }


    // creates timestamp from given date/time information
     public static String TimeStampEncode(Calendar time)
     {
       int year = time.get(Calendar.YEAR);
       int month = time.get(Calendar.MONTH) + 1;
       int day = time.get(Calendar.DAY_OF_MONTH);
       int hour = time.get(Calendar.HOUR_OF_DAY);
       int minute = time.get(Calendar.MINUTE);
       int second = time.get(Calendar.SECOND);
       int zone = time.get(Calendar.ZONE_OFFSET)/(60*60*1000)*4;
       String year_str =  String.valueOf(year);
       String month_str = String.valueOf(month);
       String day_str = String.valueOf(day);
       String hour_str = String.valueOf(hour);
       String minute_str = String.valueOf(minute);
       String second_str = String.valueOf(second);
       String zone_str = String.valueOf(zone);
       year_str=year_str.substring(2,4);
       if (month_str.length()<2) month_str="0" + month_str;
       if (day_str.length()<2) day_str="0" + day_str;
       if (hour_str.length()<2) hour_str="0" + hour_str;
       if (minute_str.length()<2) minute_str="0" + minute_str;
       if (second_str.length()<2) second_str="0" + second_str;
       if (zone_str.length()<2) zone_str="0" + zone_str;
       String out = year_str + month_str + day_str + hour_str + minute_str + second_str + zone_str;
       out = swapDigits(out);
       return out;
    }


    // decode timestamp from received sms
     public static GregorianCalendar TimeStampDecode(String timestamp)
     {
       timestamp = SmsPduCodec.swapDigits(timestamp);
       int year = Integer.parseInt(timestamp.substring(0,2));
       int month = Integer.parseInt(timestamp.substring(2,4)) - 1;
       int day = Integer.parseInt(timestamp.substring(4,6));
       int hour = Integer.parseInt(timestamp.substring(6,8));
       int minute = Integer.parseInt(timestamp.substring(8,10));
       int second = Integer.parseInt(timestamp.substring(10,12));
       int zone = Integer.parseInt(timestamp.substring(10,12))*(60*60*1000)/4;
       GregorianCalendar time= new GregorianCalendar(year,month,day,hour,minute,second);
       return time;
    }

   
    // Conversion: 8 bit bytes as hex strings --> 8 bit characters string
    public static String eightBitDecode(String encmsg)
	throws NumberFormatException {
	// encmsg: encoded string to decode.
	// msglen: the requested number of characters to decode.

	int i, o;
	StringBuffer msg = new StringBuffer(160);
	String ostr;
	char c;

	// assumes even number of chars in octet string.
	for(i=0; i<encmsg.length(); i=i+2) {
	    ostr = encmsg.substring(i, i+2);
	    o = Integer.parseInt(ostr, 16);
            c= (char) o;
            c = gsmToIsoMap[c];
            msg.append(c);
        }
	return msg.toString();
    }


    // class initialization.
    static {
	// construct GSM alphabet to/from ISO mappings.
	char[] gsmiso = { 0, '@', 1, '