Time server 1:55:50 wrong!! how could this be??

Question

Hello everybody,
I am develloping an application where I get the time from a time sever and update the (embedded) system time. But I am getting from the server 1h55min minutes earlier than it should be. Most of it I think come from my GMT+0200 location but that would still leave me with a 4/5 minutes advance when corrected!!
I got the program from somewhere around the net but it's too complex for me (okay okay, you can call me a noob) to find out if any of the byte handling could be the source of the error
So I have 2 questions:
1. What could be causing the illogical 11min time difference?? (I think the encodeTimestamp method is not that reliable)...
2. How do I retrieve GMT related information to such as time zone and daylight savings time??
This is the code:
package general;
import java.io.*;
import java.util.*;
import javax.microedition.io.*;
import javax.microedition.midlet.*;
import com.siemens.icm.io.*;
public class Teste27 extends MIDlet
     private ATListener ComList = null;     
     private ATCommand ATCmd = null;
     String gprs = null;
     Calendar cal;
     Date date;
     TimeZone timeZone;
     long milliSeconds = 0;
     class ATListener implements ATCommandListener{
          public void ATEvent(String Event){System.out.println("\rURC-Event: " + Event);}
          public void RINGChanged (boolean SignalState){System.out.println("\rRING-Event: " + SignalState);}
          public void DCDChanged (boolean SignalState){System.out.println("\rDCD-Event: " + SignalState);}
          public void DSRChanged (boolean SignalState){System.out.println("\rDSR-Event: " + SignalState);}
          public void CONNChanged (boolean SignalState){System.out.println("\rCONN-Event: " + SignalState);}
     public Teste27() throws MIDletStateChangeException
          System.out.println("Constructor");
          try{
               // Create Listener
               ComList = new ATListener();
               ATCmd = new ATCommand(false);
               ATCmd.addListener(ComList);
          }catch(ATCommandFailedException e){System.out.println("\rATCommandFailedException(Teste27)" + e);
          destroyApp(true);}
     protected void startApp() throws MIDletStateChangeException
          // Address
          String address = "datagram://ntp-sop.inria.fr:123";
          System.out.println(address);
          try
               // Configure GPRS connection
               gprs = ATCmd.send("at^sjnet=gprs,a2bouygtel.com,\"\",\"\",\"\",0\r");
               System.out.println(gprs);
               // Creates Connection
               System.out.println("Creating connection");
               DatagramConnection connection = (DatagramConnection)Connector.open(address);
               // Creates UDP Packet
               System.out.println("Creating message");
               byte[] buf = new NtpMessage().toByteArray();
               // Sends Packet
               System.out.println("Sending packet");
               Datagram packet = connection.newDatagram(buf,buf.length,address);        
               connection.send(packet);
               // Get response
               System.out.println("receiving connection");
               Datagram response = connection.newDatagram(512);
               connection.receive(response);
               System.out.println("Obtained");
               NtpMessage msg = new NtpMessage(response.getData());
               System.out.println(msg.toString());
               System.out.println(msg.transmitTimestamp);
               destroyApp(true);
          } catch(IOException ioe){ioe.printStackTrace();}
          catch(Exception e){System.out.println("Exception(configureSocketService): " + e);}
     protected void pauseApp()
          System.out.println("pauseApp");
     protected void destroyApp(boolean arg0) throws MIDletStateChangeException
          System.out.println("destroyApp");
          this.notifyDestroyed();
}And this is the NtpMessage Class:
package general;
import java.util.Date;
import java.util.Random;
* @author Adam Buckley
public class NtpMessage
     public byte leapIndicator = 0;
     public byte version = 3;
     public byte mode = 0;
     public short stratum = 0;
     public byte pollInterval = 0;
     public byte precision = 0;
     public double rootDelay = 0;
     public double rootDispersion = 0;
     public byte[] referenceIdentifier = {0, 0, 0, 0};
     public double referenceTimestamp = 0;
     public double originateTimestamp = 0;
     public double receiveTimestamp = 0;
     public double transmitTimestamp = 0;
      * Constructs a new NtpMessage from an array of bytes.
      */     public NtpMessage(byte[] array)
          // See the packet format diagram in RFC 2030 for details
          // BYTE 1
          leapIndicator = (byte) ((array[0] >> 6) & 0x3);
          version = (byte) ((array[0] >> 3) & 0x7);
          mode = (byte) (array[0] & 0x7);
          // BYTE 2
          stratum = unsignedByteToShort(array[1]);
          // BYTE 3
          pollInterval = array[2];
          // BYTE 4
          precision = array[3];
          // BYTES 5->8
          rootDelay = (array[4] * 256.0) +
               unsignedByteToShort(array[5]) +
               (unsignedByteToShort(array[6]) / 256.0) +
               (unsignedByteToShort(array[7]) / 65536.0);
          // BYTES 9->12
          rootDispersion = (unsignedByteToShort(array[8]) * 256.0) +
               unsignedByteToShort(array[9]) +
               (unsignedByteToShort(array[10]) / 256.0) +
               (unsignedByteToShort(array[11]) / 65536.0);
          // BYTES 13->16
          referenceIdentifier[0] = array[12];
          referenceIdentifier[1] = array[13];
          referenceIdentifier[2] = array[14];
          referenceIdentifier[3] = array[15];
          // BYTES 17->24
          referenceTimestamp = decodeTimestamp(array, 16);
          // BYTES 25->32
          originateTimestamp = decodeTimestamp(array, 24);
          // BYTES 33-40
          receiveTimestamp = decodeTimestamp(array, 32);
          // BYTES 41-48
          transmitTimestamp = decodeTimestamp(array, 40);
      * Constructs a new NtpMessage in client -> server mode, and sets the
      * transmit timestamp to the current time.
     public NtpMessage()
          // Note that all the other member variables are already set with
          // appropriate default values.
          this.mode = 3;
          this.transmitTimestamp = (System.currentTimeMillis()/1000.0) + 2208988800.0;
      * This method constructs the data bytes of a raw NTP packet.
      */     public byte[] toByteArray()
          // All bytes are automatically set to 0
          byte[] p = new byte[48];
          p[0] = (byte) (leapIndicator << 6 | version << 3 | mode);
          p[1] = (byte) stratum;
          p[2] = (byte) pollInterval;
          p[3] = (byte) precision;
          // root delay is a signed 16.16-bit FP, in Java an int is 32-bits
          int l = (int) (rootDelay * 65536.0);
          p[4] = (byte) ((l >> 24) & 0xFF);
          p[5] = (byte) ((l >> 16) & 0xFF);
          p[6] = (byte) ((l >> 8) & 0xFF);
          p[7] = (byte) (l & 0xFF);
          // root dispersion is an unsigned 16.16-bit FP, in Java there are no
          // unsigned primitive types, so we use a long which is 64-bits
          long ul = (long) (rootDispersion * 65536.0);
          p[8] = (byte) ((ul >> 24) & 0xFF);
          p[9] = (byte) ((ul >> 16) & 0xFF);
          p[10] = (byte) ((ul >> 8) & 0xFF);
          p[11] = (byte) (ul & 0xFF);
          p[12] = referenceIdentifier[0];
          p[13] = referenceIdentifier[1];
          p[14] = referenceIdentifier[2];
          p[15] = referenceIdentifier[3];
          encodeTimestamp(p, 16, referenceTimestamp);
          encodeTimestamp(p, 24, originateTimestamp);
          encodeTimestamp(p, 32, receiveTimestamp);
          encodeTimestamp(p, 40, transmitTimestamp);
          return p;
      * Returns a string representation of a NtpMessage
      */     public String toString()
          return "Leap indicator: " + leapIndicator + "\r\n" +
               "Version: " + version + "\r\n" +
               "Mode: " + mode + "\r\n" +
               "Stratum: " + stratum + "\r\n" +
               "Poll: " + pollInterval + "\r\n" +
//               "Precision: " + precision + " (" + precisionStr + " seconds)\r\n" +
//               "Root delay: " + new DecimalFormat("0.00").format(rootDelay*1000) + " ms\r\n" +
//               "Root dispersion: " + new DecimalFormat("0.00").format(rootDispersion*1000) + " ms\r\n" +
               "Reference identifier: " + referenceIdentifierToString(referenceIdentifier, stratum, version) +
"\r\n" +
               "Reference timestamp: " + timestampToString(referenceTimestamp) + "\r\n" +
               "Originate timestamp: " + timestampToString(originateTimestamp) + "\r\n" +
               "Receive timestamp:   " + timestampToString(receiveTimestamp) + "\r\n" +
               "Transmit timestamp:  " + timestampToString(transmitTimestamp);
      * Converts an unsigned byte to a short.  By default, Java assumes that
      * a byte is signed.
      */     public static short unsignedByteToShort(byte b)
          if((b & 0x80)==0x80) return (short) (128 + (b & 0x7f));
          else return (short) b;
      * Will read 8 bytes of a message beginning at <code>pointer</code>
      * and return it as a double, according to the NTP 64-bit timestamp
      * format.
     public static double decodeTimestamp(byte[] array, int pointer)
          double r = 0.0;
          for(int i=0; i<8; i++)
//               r += unsignedByteToShort(array[pointer+i]) * Math.pow(2, (3-i)*8);
            double tmp = unsignedByteToShort(array[pointer+i]);           
            for(int k=0;k<(3-i)*8;k++)
                tmp *= 2;
            r += tmp;
          return r;
      * Encodes a timestamp in the specified position in the message
     public static void encodeTimestamp(byte[] array, int pointer, double timestamp)
          // Converts a double into a 64-bit fixed point
          for(int i=0; i<8; i++)
               // 2^24, 2^16, 2^8, .. 2^-32
//               double base = Math.pow(2, (3-i)*8);
               double base = 1;      
               for(int k=0;k<(3-i)*8;k++)
                   base *= 2;
               // Capture byte value
               array[pointer+i] = (byte) (timestamp / base);
               // Subtract captured value from remaining total
               timestamp = timestamp - (double) (unsignedByteToShort(array[pointer+i]) * base);
          // From RFC 2030: It is advisable to fill the non-significant
          // low order bits of the timestamp with a random, unbiased
          // bitstring, both to avoid systematic roundoff errors and as
          // a means of loop detection and replay detection.
//          array[7] = (byte) (Math.random()*255.0);
        array[7+pointer] = (byte) (new Random(System.currentTimeMillis()).nextDouble()*255.0);
      * Returns a timestamp (number of seconds since 00:00 1-Jan-1900) as a
      * formatted date/time string.
     public static String timestampToString(double timestamp)
          if(timestamp==0) return "0";
          // timestamp is relative to 1900, utc is used by Java and is relative
          // to 1970
          double utc = timestamp - (2208988800.0);
          // milliseconds
          long ms = (long) (utc * 1000.0);
          // date/time
//          String date = new SimpleDateFormat("dd-MMM-yyyy HH:mm:ss").format(new Date(ms));
        String date = new Date(ms).toString();
          // fraction
//          double fraction = timestamp - ((long) timestamp);
//          String fractionSting = new DecimalFormat(".000000").format(fraction);
//          String fractionString = new
//          return date + fractionSting;
        return date;
      * Returns a string representation of a reference identifier according
      * to the rules set out in RFC 2030.
     public static String referenceIdentifierToString(byte[] ref, short stratum, byte version)
          // From the RFC 2030:
          // In the case of NTP Version 3 or Version 4 stratum-0 (unspecified)
          // or stratum-1 (primary) servers, this is a four-character ASCII
          // string, left justified and zero padded to 32 bits.
          if(stratum==0 || stratum==1)
               return new String(ref);
          // In NTP Version 3 secondary servers, this is the 32-bit IPv4
          // address of the reference source.
          else if(version==3)
               return unsignedByteToShort(ref[0]) + "." +
                    unsignedByteToShort(ref[1]) + "." +
                    unsignedByteToShort(ref[2]) + "." +
                    unsignedByteToShort(ref[3]);
          // In NTP Version 4 secondary servers, this is the low order 32 bits
          // of the latest transmit timestamp of the reference source.
          else if(version==4)
               return "" + ((unsignedByteToShort(ref[0]) / 256.0) +
                    (unsignedByteToShort(ref[1]) / 65536.0) +
                    (unsignedByteToShort(ref[2]) / 16777216.0) +
                    (unsignedByteToShort(ref[3]) / 4294967296.0));
          return "";
}   Thank you (if you got this far... =s)

Answer 1

i forgot to mention one thing in my previous post..
my server starts up sometimes without giving me any problems. that is, when i face this problem, all i do is shut down the server and then wait for abt 10-15 minutes and try starting it again..sometimes this gap of 15 min helps a lot coz the server starts up properly and the connection exception does not occur. Also,the web app also works perfectly. But this wasnt the case abt 2 months back. prior to this problem, my server would never give me a problem and i could start and stop it at will...i used to start and stop the server almost 3-4 times a day (when i made changes to java files and wanted the server to read the latest class files..).it was only 2 months back that this problem arose and ever since then, all i would do is wait for 10-15 minutes if the server doesnt start up and then try my luck again. Even if i wait for 15 min, there are days when the server doesnt start properly all day long !
Another issue is that even when the server starts properly(without giving the connection exception) it sometimes does not load the web application correctly. It displays a "Page cannot be found" error. But waiting for abt 10-15 minutes again removes this problem and i am again able to use the application.
I am a newbie to JAVA and do not know much abt application servers. I had read through the Apache tomcat documentation which told me abt JNDI realm and the 389 port to which connection is made. I could not understand much and thats why i posted the problem on this forum.
This whimsical behaviour is what has delayed my work and i am not being able to deliver on deadlines.Needless to say, any help would be appreciated. :)
Regards,
Shankar