The native C implementation provides a fields implemention. The various subtypes though of fields, such as Administration messages are not supplied. A number of helper methods are provided to help construct the usual WebSphere MQ Everyplace Messages.
Various other subclasses of message can be constructed from a basic fields object, the required constants for the field labels, and the mqeFIelds_setClassName method. This method sets a field indicated what class this must be when reinstantiated in a Java queue manager.