WAS v8.5 > WebSphere applications > Messaging resources > Interoperation with WebSphere MQ > Interoperation using the WebSphere MQ messaging providerWebSphere MQ messages
A WebSphere MQ message usually contains a message descriptor, one or more message headers, and a message payload. WebSphere MQ provides programming interfaces that can help the applications to process WebSphere MQ messages.
Components of a WebSphere MQ message
A WebSphere MQ message contains one or more of the following components:
- Message descriptor
- The message descriptor contains standard message properties, applicable to all WebSphere MQ messages. For example, the message descriptor contains the message identifier and the correlation identifier (similar to the JMSMessageID and the JMSCorrelationID). Every WebSphere MQ message contains a message descriptor (MQMD).
- Message headers
- A message header usually contains additional message properties applicable to particular types of message. For example, WebSphere MQ messages sent to the CICS bridge include a CICS bridge header (MQCIH). One exception is the "WebSphere MQ rules and formatting header 2" (MQRFH2), which can be used to contain message properties for various message types, including JMS message properties. Which headers (if any) a WebSphere MQ message contains depends on the intended recipient.
- Message Properties
- WebSphere MQ message properties were introduced with the WebSphere MQ v7.0 JMS client. A WebSphere MQ message property is data associated with a message, consisting of a textual name and a value of a particular type. WebSphere MQ message properties are used by message selectors to filter publications to topics or to selectively get messages from queues. WebSphere MQ message properties can be used to include business data or state information without having to store it in the application data. Applications do not have to access data in the MQMD or MQRFH2 headers because the fields in these data structures can be accessed as WebSphere MQ message properties.
- Message payload
- The message payload is the data (if any) that follows the last message header, or that follows the MQMD if there are no message headers.
For more information about WebSphere MQ messages, see the Application Programming Guide and Application Programming Reference sections of the WebSphere MQ information center.
WebSphere MQ implementation of a JMS message
WebSphere MQ provides a programming interface called the Message Queue Interface (MQI). This interface allows applications to process the components of a WebSphere MQ message using a variety of programming languages. WebSphere MQ also provides a JMS programming interface which allows applications to process a WebSphere MQ message as a JMS message. In this case the JMS message body is usually the WebSphere MQ message payload. However the JMS message body can include WebSphere MQ message headers or, if you are using WebSphere MQ v7.x, WebSphere MQ message properties, or both. For details of WebSphere MQ support for JMS, see the Use Java section of the WebSphere MQ information center.
Reference:
WebSphere MQ messaging provider queue and topic advanced properties settings
WebSphere MQ Provider queue destination settings for application clients
WebSphere MQ Provider topic destination settings for application clients