Data conversion

This collection of topics describes the interface to the data-conversion exit, and the processing performed by the queue manager when data conversion is required.

For more information about data conversion, see the document Data Conversion under IBM MQ at https://www.ibm.com/support/pages/node/317869.

The data-conversion exit is invoked as part of the processing of the MQGET call in order to convert the application message data to the representation required by the receiving application. Conversion of the application message data is optional; it requires the MQGMO_CONVERT option to be specified on the MQGET call.

• The processing performed by the queue manager in response to the MQGMO_CONVERT option; see Conversion processing.
• Processing conventions used by the queue manager when processing a built-in format; these conventions are recommended for user-written exits too. See Processing conventions.
• Special considerations for converting report messages; see Conversion of report messages.
• The parameters passed to the data-conversion exit; see MQ_DATA_CONV_EXIT - Data conversion exit.
• A call that can be used from the exit to convert character data between different representations; see MQXCNVC - Convert characters.
• The data-structure parameter that is specific to the exit; see MQDXP - Data-conversion exit parameter.

• Conversion processing
  This information describes the processing performed by the queue manager in response to the MQGMO_CONVERT option.
• Processing conventions
  When converting a built-in format, the queue manager follows the processing conventions described.
• Conversion of report messages
  In general a report message can contain varying amounts of application message data, according to the report options specified by the sender of the original message. However, an activity report can contain data but without the report option mentioning *_WITH_DATA in the constant.
• MQDXP - Data-conversion exit parameter
  The MQDXP structure is a parameter that the queue manager passes to the data-conversion exit when the exit is invoked to convert the message data as part of the processing of the MQGET call. See the description of the MQ_DATA_CONV_EXIT call for details of the data conversion exit.
• MQXCNVC - Convert characters
  The MQXCNVC call converts characters from one character set to another using the C programming language.
• MQ_DATA_CONV_EXIT - Data conversion exit
  The MQ_DATA_CONV_EXIT call describes the parameters that are passed to the data-conversion exit.

Parent topic: MQI applications reference