Miscellaneous differences between IBM MQ classes for Java on z/OS and other platforms

IBM MQ for z/OS® behaves differently from IBM MQ on other platforms in some areas.

BackoutCount

A z/OS queue manager returns a maximum BackoutCount of 255, even if the message has been backed out more than 255 times.

Default dynamic queue prefix

When connected to a z/OS queue manager using a bindings connection, the default dynamic queue prefix is CSQ.*. Otherwise, the default dynamic queue prefix is AMQ.*.

MQQueueManager constructor

Client connect is not supported on z/OS. Attempting to connect with client options results in an MQException with MQCC_FAILED and MQRC_ENVIRONMENT_ERROR.

The MQQueueManager constructor might also fail with MQRC_CHAR_CONVERSION_ERROR (if it fails to initialize conversion between the IBM-1047 and ISO8859-1 code pages), or MQRC_UCS2_CONVERSION_ERROR (if it fails to initialize conversion between the queue manager's code page and Unicode). If our application fails with one of these reason codes, ensure that the National Language Resources component of Language Environment is installed, and ensure that the correct conversion tables are available.

Conversion tables for Unicode are installed as part of the z/OS C/C++ optional feature. See the z/OS C/C++ Programming Guide, SC09-4765, for more information about enabling UCS-2 conversions.