Archive for the Category: Java

Java’s Missing Byte Array Class

February 19, 2020 Roger Lacroix

After 25 years, it is still surprising that Java doesn’t have a proper byte array class. There can be many reasons that the data a Java program needs to work with is in a byte array. It could be the contents of a file or MQTT message or IBM MQ message, etc. Since there is […]

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Inhibit/Allow the Get & Put Actions of a Queue

January 31, 2020 Roger Lacroix

On StackOverflow, someone asked a question about inhibiting get actions against a queue. Here is a simple Java/MQ program that will set inhibit or allow for the GET and PUT attributes of a queue. You can download the source code from here. Regards, Roger Lacroix Capitalware Inc.

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Request & Reply JMS/MQRFH2 Messaging Scenario

January 31, 2020 Roger Lacroix

Sometimes people over think a problem and write a complicated solution when really the solution is no different than any other Request/Reply scenario (use case). On StackOverflow, someone asked a question about sending a reply JMS/MQRFH2 message using the RFH2 header and folder values from the original request message. The code will copy the RFH2 […]

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JMS/MQRFH2 Message Properties in “other” Folder

January 17, 2020 Roger Lacroix

On StackOverflow, someone asked about having an “other” folder (not “usr”) with an MQRFH2 (aka JMS) message. That day, I played around with a MQ/Java program that created various folders in an MQRFH2 message. i.e. When I ran a MQ/JMS program to retrieve the messages, the MQ/JMS programs simply ignore all folders outside of ‘mcd’, […]

Also posted in C, IBM i (OS/400), IBM MQ, JMS, Linux, macOS (Mac OS X), Programming, Unix, Windows, z/OS Comments Off on JMS/MQRFH2 Message Properties in “other” Folder

MQ Internals Explained (a little bit)

December 10, 2019 Roger Lacroix

IBM likes to market IBM MQ (aka WebSphere MQ, MQSeries) as a simple and complete solution for business’s messaging needs. Going with the KISS approach is wise (very wise in some cases). IBM talks about the 2 different messaging models that IBM MQ supports: Point-to-Point (P2P) and Publish/Subscribe (Pub/Sub). IBM will: show you how to […]

Also posted in .NET, Assembler, C, C#, C++, HPE NonStop, IBM i (OS/400), IBM MQ, JMS, Linux, macOS (Mac OS X), MQ Auditor, MQ Message Encryption, Programming, Unix, Windows, z/OS 2 Comments

Java on Windows 10 Issue: “Could not open/create prefs root node”

November 22, 2019 Roger Lacroix

I was getting the following error message when I would run a Java application on my new Windows 10 Pro PC: I searched the internet regarding the error message, people say it is a known bug and you need to manually create the following Windows registry key: When I opened the RegEdit, I found that […]

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Windows and UHD 4K Resolution

October 7, 2019 Roger Lacroix

Another interesting problem/issue that I’ve come across while installing software on my new ASUS ZenBook Pro laptop was that some older 32-bit applications don’t show the images, toolbar icons, etc. correctly. The applications are not “DPI Aware” but for Windows 10, it defaults to applications being “DPI Aware”. Hence, if you can upgrade to a […]

Also posted in JMS, Windows Comments Off on Windows and UHD 4K Resolution

2 New IBM MQ RFEs related to com.ibm.mq.jmqi.defaultMaxMsgSize

September 20, 2019 Roger Lacroix

Please review and vote for these RFEs if you think they are a good idea. The links below will take you directly to the RFE. RFE #1: Document com.ibm.mq.jmqi.defaultMaxMsgSize JVM environment variable URL to review the RFE and Vote for it if you like: http://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID=136680 RFE #2: Add & Document com.ibm.mq.jmqi.defaultMaxMsgSize for .NET Framework URL […]

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JMS and Java Client Mode Performance Issues for MQ Get API Calls

August 15, 2019 Roger Lacroix

I’ve wasted far, far too much of my time inspecting what is going on with the auto-resizing of the get buffer for the internal JMQI and MQI components for MQ classes for JMS, MQ classes for Java and MQ classes for .NET. A strange entry in one of the MQ Auditor audit files got my […]

Also posted in IBM i (OS/400), IBM MQ, JMS, Linux, macOS (Mac OS X), Programming, Unix, Windows, z/OS Comments Off on JMS and Java Client Mode Performance Issues for MQ Get API Calls

Pub/Sub Java/JMS MQ MQGet API Issue

August 9, 2019 Roger Lacroix

Not surprisingly, when I tested: Subscribing to a topic with JMS Subscribing to a topic with Java (non-JMS) They both showed that the internal JMQI routine was starting with a MQGet buffer size of 4KB and auto-adjusting the size of the buffer as needed (all behind the scenes). Hence, when I used MQ Auditor, I […]

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