getting null, in object transfer.

Hi,

I got a problem when sending the data from the serverside and getting
it back in the client side. We are not getting the object(here it is
DataTransferObject which is Serializable) as null in the client side.

I am putting the serverside code.

public void sendDataObjectToClient(
        HttpServletResponse res,
        DataTransferObject obj,
        String accepts) {

        ByteArrayOutputStream bos = null;
        ObjectOutputStream oos = null;
        ServletOutputStream sos = null;
        boolean didCompress = false;
        try {
            sos = res.getOutputStream();
            bos = new ByteArrayOutputStream();
            oos = new ObjectOutputStream(bos);
            oos.writeObject(obj);
            oos.flush();
            oos.close();
            byte[] bytes = bos.toByteArray();
            int origLength = bytes.length;
            if ((bytes.length > 1024 * 2)
                && accepts != null
                && accepts.indexOf("gzip") >= 0) { // large response, compress it.
                ByteArrayOutputStream zbaos = new ByteArrayOutputStream();
                GZIPOutputStream zo = new GZIPOutputStream(zbaos);
                zo.write(bytes);
                zo.flush();
                zo.close();
                bytes = zbaos.toByteArray();
                log.debug(
                    "Writing compressed response, orig="
                        + origLength
                        + " new length="
                        + bytes.length);
                didCompress = true;
            } else {
                log.debug("Writing response, length=" + bytes.length);
            }
            res.setContentType("application/x-java-serialized-object");
            res.setContentLength(bytes.length);
            if (didCompress == true) {
                res.setHeader("Content-encoding", "gzip");
            }
            try {
                sos.write(bytes);
                sos.flush();
            } catch (IOException ioerror) {
                log.info("I/O Error to Client " + ioerror.toString());
            }
        } catch (Exception e) {
            log.error("Unexpected error sending data to client", e);
        } finally {
            if (sos != null) {
                try {
                    sos.close();
                } catch (Exception ignored) {
                }
            }
        }
}

We are using java 1.3 at serverside and 1.4 at the clientside.

And also this problem is not occuring continuously, sometimes we are
getting the object and some times its null. What could be the reason
behind this.

This is very critical for us, any possible solution would be really
helpful for us.

Thanks in advance.