Name: tb29552 Date: 05/06/99


/*
Hi there,
We have a problem with ByteArrayInputStream or DataInputStream.
We don't know where the problem exactly happens, probably in
ByteArrayInputStream. In just one case we get an exception if the
stream is of a certain size, if we add/remove a blank or character to the
stream, the problem doesn't exist (no exception). We have also tried
JDK 1.1.8 but the problem persists.
Here is the test case:

program which simulates the following situation:

In the sending part, a Vector is written into a stream and then into a
String Then a int (count), the converted Vector and the CRC of the
converted Vector are again written into a stream, which is then
converted into a String.

In the receiving part, the String is attempted to read into a stream,
and normally put in a String Array.

What happens is this:
% javac testsendstream.java
% java -Djava.compiler=NONE testsendstream
to second stream: 000104FGEEEDftFFFekt00070001
                                              chosen type0002
                                                             chosen brand0003
                                                                             config name0004group00060012
to send: 2000???0001??04??FGEEEDftFFFekt??0007??0001??
                                                      chosen type??0002??
                                                                         chosen brand??0003??
             config name??0004??group??0006??00120000000000908106492
??0001??04??FGEEEDftFFFekt??0007??0001??
                                        chosen type??000
IOException: receiveString
   incrcstring contains: null
java.io.EOFException
        at java.io.DataInputStream.readUnsignedByte(DataInputStream.java:247)
        at java.io.DataInputStream.readUTF(DataInputStream.java:526)
        at java.io.DataInputStream.readUTF(DataInputStream.java:498)
        at testsendstream.main(testsendstream.java:156)
CRC not correct



*/

import java.util.*;
import java.util.zip.*;
import java.io.*;
import java.lang.reflect.*;

class testsendstream {

    public static void main(String args[]) {

        /** sending part*/

        ByteArrayOutputStream byteoutstream = new ByteArrayOutputStream();
        DataOutputStream dataoutstream = new DataOutputStream(byteoutstream);
        byteoutstream.reset();

        boolean fpfound = false;
        int count = 0;

        Vector vect = new Vector();

        vect.addElement(new Integer(4));
        vect.addElement(new String("FGEEEDftFFFekt"));
        vect.addElement(new Integer(7));
        vect.addElement(new Integer(1));
        vect.addElement(new String("chosen type")); // <- add/remove a blank
                                                        // or character and it
                                                        // works
        vect.addElement(new Integer(2));
        vect.addElement(new String("chosen brand"));
        vect.addElement(new Integer(3));
        vect.addElement(new String("config name"));
        vect.addElement(new Integer(4));
        vect.addElement(new String("group"));
        vect.addElement(new Integer(6));
        vect.addElement(new Integer(12));

        int cmd = 0x2000;
        int cmdtest = ((Integer) vect.elementAt(0)).intValue();

        int[] posdigact = {1, 2, 3, 4, 6};

        count++;
        try {
            dataoutstream.writeUTF(convertInt(4, count)); // count
            dataoutstream.writeUTF(convertInt(2, cmdtest)); // Number
            dataoutstream.writeUTF((String) vect.elementAt(1)); // ID
            dataoutstream.writeUTF(convertInt(4, ((Integer) vect.elementAt(2)).intValue())); // Number
            dataoutstream.writeUTF(convertInt(4, ((Integer) vect.elementAt(3)).intValue())); // Field pos
            dataoutstream.writeUTF((String) vect.elementAt(4)); // Value
            dataoutstream.writeUTF(convertInt(4, ((Integer) vect.elementAt(5)).intValue())); // Field pos
            dataoutstream.writeUTF((String) vect.elementAt(6)); // Value
            dataoutstream.writeUTF(convertInt(4, ((Integer) vect.elementAt(7)).intValue())); // Field pos
            dataoutstream.writeUTF((String) vect.elementAt(8)); // Value
            dataoutstream.writeUTF(convertInt(4, ((Integer) vect.elementAt(9)).intValue())); // Field pos
            dataoutstream.writeUTF((String) vect.elementAt(10)); // Value
            dataoutstream.writeUTF(convertInt(4, ((Integer) vect.elementAt(11)).intValue())); // Field pos
            dataoutstream.writeUTF(convertInt(4, ((Integer) vect.elementAt(12)).intValue())); // Value
        }
        catch(IOException e) {
            System.out.println("IOException");
            e.printStackTrace();
        }

        String framestring = byteoutstream.toString();

        System.out.println("to second stream: " + framestring);

        String command = Integer.toHexString(cmd);

        ByteArrayOutputStream byteoutstream2 = new ByteArrayOutputStream();
        DataOutputStream dataoutstream2 = new DataOutputStream(byteoutstream2);
        byteoutstream2.reset();
        byte[] crcbyte = framestring.getBytes();
        CRC32 crc = new CRC32();
        crc.reset();
        crc.update(crcbyte);
        try {
            dataoutstream2.writeUTF(command);
            dataoutstream2.writeUTF(framestring);
            String crcstringvalue = convertLong(crc.getValue());
            dataoutstream2.writeUTF(crcstringvalue);
            dataoutstream2.flush();
            dataoutstream2.close();
        }
        catch(IOException e) {
            System.out.println("IOException sendString");
            e.printStackTrace();
        }
        String sendstring = byteoutstream2.toString();

        System.out.println("to send: " + sendstring);

        String received = sendstring;

        /**receiving part */


        String[] s = new String[2];
        String incrcstring=null;
        long incrc = 0;

        byte[] inbyte = received.getBytes();
        ByteArrayInputStream byteinstream = new ByteArrayInputStream(inbyte);
        DataInputStream datainstream = new DataInputStream(byteinstream);
        byteinstream.reset();

        try {
            s[0] = datainstream.readUTF(); // command
            s[1] = datainstream.readUTF(); // instring
            System.out.println(s[1]);
            incrcstring = datainstream.readUTF();
            incrc = Long.parseLong(incrcstring);
        }
        catch(IOException e) {
            System.out.println("IOException: receiveString");
            System.out.println(" incrcstring contains: " + incrcstring);
            
            e.printStackTrace();
        }


        byte[] crcbyte2 = s[1].getBytes();
        CRC32 crc2 = new CRC32();
        crc2.reset();
        crc2.update(crcbyte2);

        if (crc2.getValue() == incrc)
            System.out.println("Frame correctly received");
        else
            System.out.println("CRC not correct");

    }

    synchronized static String convertInt(int max, int toconvert) {

        String converted = new String();
        String temp;

        temp = String.valueOf(toconvert);
        int le = temp.length();

        for (int i = 0; i < (max - le); i++)
            converted += "0";
        converted += temp;

        return converted;
    }


    synchronized static String convertLong(long longnumber) {
        String converted = new String();
        String temp;

        temp = String.valueOf(longnumber);
        int le = temp.length();

        for (int i = 0; i < (19 - le); i++)
            converted += "0";
        converted += temp;

        return converted;
    }
}

/*

The blank/character can be added/removed in any of the above strings
and the problem doesn't occur. We are about to program a
communication protocol for Internet communication any need a solution
to this problem urgently.
Any ideas?
For any questions, don't hesitate to contact us at
###@###.### (Peter) or
###@###.### (Georg)

Best regards
Peter

*/
(Review ID: 57890)
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