How to handle the RFH2 header in C# from IBM WMQ?

Question

I'm reading messages from IBM WMQ in C#. I need to read the message Id. Currently when attempting to read it, it's not readable.

I think it may be because the messages contain RFH2 headers and I need to handle them before consuming the messages however I'm not sure how to exactly do this?

C# code:

try
{
    MQMessage queueMessage;
    MQGetMessageOptions queueGetMessageOptions;
    string message = string.Empty;
    queueMessage = new MQMessage();
    queueMessage.Format = MQC.MQFMT_STRING;
    queueGetMessageOptions = new MQGetMessageOptions { WaitInterval = _appSettings.MqProperties.WaitIntervalMs };
    queueGetMessageOptions.Options |= MQC.MQGMO_WAIT;
    queueGetMessageOptions.Options |= MQC.MQGMO_SYNCPOINT;
    queue.Get(queueMessage, queueGetMessageOptions);

    if (queueMessage.Format.CompareTo(MQC.MQFMT_STRING) == 0)
    {
        if (queueMessage.MessageLength > 0)
        {
            message = queueMessage.ReadString(queueMessage.MessageLength);
            _logger.LogInfo(LogStatus.InProgress, $"Message: {message}.");
            _logger.LogInfo(LogStatus.InProgress, $"Message ID length: {queueMessage.MessageId.Length}.MessageId: {Encoding.UTF8.GetString(queueMessage.MessageId, 0, queueMessage.MessageId.Length)}");
            _logger.LogInfo(LogStatus.InProgress, $"Message ID length: {queueMessage.MessageId.Length}.MessageId: {Encoding.ASCII.GetString(queueMessage.MessageId, 0, queueMessage.MessageId.Length)}");
            _logger.LogInfo(LogStatus.InProgress, $"Message ID length: {queueMessage.MessageId.Length}.MessageId: {Encoding.Default.GetString(queueMessage.MessageId, 0, queueMessage.MessageId.Length)}");
            _logger.LogInfo(LogStatus.InProgress, $"Message ID length: {queueMessage.MessageId.Length}.MessageId: {Encoding.Unicode.GetString(queueMessage.MessageId, 0, queueMessage.MessageId.Length)}");
            _logger.LogInfo(LogStatus.InProgress, $"Message ID length: {queueMessage.MessageId.Length}.MessageId: {Encoding.Latin1.GetString(queueMessage.MessageId, 0, queueMessage.MessageId.Length)}");
            _logger.LogInfo(LogStatus.InProgress, $"Message ID length: {queueMessage.MessageId.Length}.MessageId: {Encoding.UTF32.GetString(queueMessage.MessageId, 0, queueMessage.MessageId.Length)}");
            _logger.LogInfo(LogStatus.InProgress, $"Message ID length: {queueMessage.MessageId.Length}.MessageId: {Encoding.BigEndianUnicode.GetString(queueMessage.MessageId, 0, queueMessage.MessageId.Length)}");

            await _messageConsumer.ConsumeMessage(message, Encoding.UTF8.GetString(queueMessage.MessageId, 0, queueMessage.MessageId.Length));
        }
        else
        {
            _logger.LogInfo(LogStatus.InProgress, $"INVALID MESSAGE. Message Length {queueMessage.MessageLength}");
        }
    }
    else
    {
        _logger.LogInfo(LogStatus.InProgress, $"UNRECOGNISED MESSAGE FORMAT");
    }
}
catch (MQException mqex)
{
    if (mqex.Reason == MQC.MQRC_NO_MSG_AVAILABLE)
    {
        _logConstants.InitializeCorrelationIdAndKeysForEachRun();
        _logConstants.InitializeLoggerKeys(null, null);
        _logger.LogInfo(LogStatus.InProgress, $"{mqex.ReasonCode} {mqex.Message} CurrentDepth: {queue.CurrentDepth}. MaximumDepth {queue.MaximumDepth}");
    }
    else if (mqex.Reason == MQC.MQRC_Q_MGR_STOPPING)
    {
        _logger.LogError(
            LogErrors.ErrorWhileConsumingMsgFromIBMMQ,
            LogStatus.Failed,
            "IBM MQ Consumer Error",
            $" Error in Consuming the message from MQ. Making the thread sleep for one minute");

        await Task.Delay(60000, cancellationToken);
    }
    else
    {
        _logger.LogError(
            LogErrors.ErrorWhileConsumingMsgFromIBMMQ,
            LogStatus.Failed,
            "IBM MQ Consumer Error",
            $" Error in Consuming the Message from MQ {mqex.Reason} {mqex.Message} {mqex.StackTrace}");

        await Task.Delay(60000, cancellationToken);
        queueManager = null;
        queue = null;
    }
}

Update:

Following the comments on here, I tried the following:

_logger.LogInfo(LogStatus.InProgress, $"Message ID length: {queueMessage.MessageId.Length}.MessageId: {queueMessage.MessageId.ByteArrayToString}");

public static string ByteArrayToString(this byte[] ba)
{
    return BitConverter.ToString(ba).Replace("-", "");
}

However that outputs:

Message ID length: 24.MessageId: System.Func`1[System.String]

Answer 1

This looks like a normal IBM MQ MessageId. The 24 bytes contain non-printable characters. You should Convert.ToHexString the MessageId before printing it:

string messageIdHex = Convert.ToHexString(queueMessage.MessageId);
// Now you can print this hex-encoded IBM MQ Message ID