将RFH2标头添加到IBM MQ消息的正确方法是什么

Question

I have recently started working with IBM MQ (v7.5) and currently working on a bridge like service for 2 way data transfer between MQ & another REST service I have.

By using standard APIs I am able to read and write messages without any issue. But the problem I am facing came when I started setting up MQRFH2 header to my messages. I must be doing some mistake while writing data with header because every time I am getting " End of file exception ('MQMessage.seek()'). " error while reading those messages.

This is my code snippet while putting the message into MQ:

//Constructing message
MQMessage sendmsg = new MQMessage();
sendmsg.characterSet = 1208;
sendmsg.format = MQC.MQFMT_STRING;
sendmsg.feedback = MQC.MQFB_NONE;
sendmsg.messageType = MQC.MQMT_DATAGRAM;
sendmsg.replyToQueueName = outputBackupQueueName;
sendmsg.replyToQueueManagerName = queueManager;

//Constructing header
MQRFH2 rfh2 = new MQRFH2();
rfh2.setEncoding(MQConstants.MQENC_NATIVE);
rfh2.setCodedCharSetId(MQConstants.MQCCSI_INHERIT);
rfh2.setFormat(MQConstants.MQFMT_STRING);
rfh2.setNameValueCCSID(1208);

//adding message to header
rfh2.write(sendmsg);

//payload is the actual data which we want to send
byte[] messageBytes = payload.getBytes("UTF-8");
sendmsg.write(messageBytes);

//putting message to MQ
MQPutMessageOptions outputMsgOpt = new MQPutMessageOptions();
outputMsgOpt.options = MQConstants.MQPMO_FAIL_IF_QUIESCING |
                MQConstants.MQPMO_DEFAULT_CONTEXT |
                MQConstants.MQPMO_SYNCPOINT;

outputQueue.put(sendmsg, outputMsgOpt);
queueManager.commit();

And this is how I am trying to retrieve it later:

MQMessage incomingMessage = new MQMessage();
byte[] incomingMessageId = incomingMessage.messageId;
MQGetMessageOptions gmo = new MQGetMessageOptions();
gmo.options = MQConstants.MQGMO_FAIL_IF_QUIESCING |
                        MQConstants.MQGMO_CONVERT |
                        MQConstants.MQGMO_SYNCPOINT |
                        MQConstants.MQGMO_LOGICAL_ORDER |
                        MQConstants.MQGMO_ALL_MSGS_AVAILABLE |
                        MQConstants.MQGMO_WAIT;

inputQueue.get(incomingMessage, gmo);
MQRFH2 myRfh2 = new MQRFH2(incomingMessage); //this statement throws error with headers

Complete error message is:

com.ibm.mq.headers.MQDataException: MQJE001: Completion Code '2', Reason '2195'.
    at com.ibm.mq.headers.MQDataException.getMQDataException(MQDataException.java:317)
    at com.ibm.mq.headers.internal.Header.read(Header.java:620)
    at com.ibm.mq.headers.MQRFH2.<init>(MQRFH2.java:113)
    at com.simility.util.MQRfh2HeaderHelper.getMsgByteArray(MQRfh2HeaderHelper.java:16)
    at com.simility.mq.SimilityMQBridge.main(SimilityMQBridge.java:182)

    Caused by: com.ibm.mq.headers.MQDataException: MQJE001: Completion Code '2', Reason '6114'.
    at com.ibm.mq.headers.MQDataException.getMQDataException(MQDataException.java:314)
    at com.ibm.mq.headers.MQRFH2.read(MQRFH2.java:184)
    at com.ibm.mq.headers.internal.Header.read(Header.java:639)
    at com.ibm.mq.headers.internal.Header.read(Header.java:617)
    ... 3 more

    Caused by: java.io.EOFException: MQJE086: End of file exception ('MQMessage.seek()').
    at com.ibm.mq.MQMessage.seek(MQMessage.java:716)
    at com.ibm.mq.headers.internal.store.MQMessageStore.readFrom(MQMessageStore.java:274)
    at com.ibm.mq.headers.internal.Header.read(Header.java:661)
    at com.ibm.mq.headers.MQRFH2.read(MQRFH2.java:181)

Another thing I verified is message length by "TotalMessageLength", and that matches between reading and writing the messages, but still the failure happens.

Can anyone please help me out or point me in right direction related to adding and retrieving messages with RFH2 header ?

Answer 1

Another thing I verified is message length by "TotalMessageLength", and that matches between reading and writing the messages, but still the failure happens.

Does the method "getMessageLength()" of MQMessage return the data length of the payload?

Why don't you try (in the sender):

byte[] messageBytes = payload.getBytes();

If your data is not the same codepage or encoding then let MQ do the work rather than you doing getBytes("UTF-8").

ie Set the Encoding and CCSID to what the data is.

rfh2.setEncoding(???);
rfh2.setCodedCharSetId(???);