What is a message property?
Message producers can attach arbitrary properties to outgoing messages. This data is stored in the message header, in essence, as virtual fields in the header. JMS reserves the "JMSX." property name prefix for JMS-defined properties.
Producer-defined properties are set with Message.setXXXProperty() and retrieved with Message.getXXXProperty(), where "XXX" can be Boolean, Byte, and so on. There are many property-related methods; see the JMS vendor's documentation, as well as the JMS API documentation, in particular, the description for Message, for complete property handling information.