Predefined and self-defining messages

Both predefined and self-defining messages are supported.

Each message that flows through your broker domain has a specific structure that is meaningful to the applications that send or receive that message.

WebSphere® Message Broker refers to the structure as the message template. Message template information comprises the message domain, message set, message type, andphysical format of the message. Together, these values identify the structure of the data that the message contains.

The message domain identifies the parser that is used to parse and write instances of the message. Message set, message type, and physical format are optional, and are used by model-driven parsers such as the MRM parser.

You can use:

Predefined messages

When you create a message using the workbench, you define the fields (Elements) in the message, along with any special field types that you might need, and any specific values (Value Constraints) to which the fields might be restricted.

Every message that you model in the workbench must be a member of a message set. You can group related messages together in a message set: for example, request and response messages for a bank account query can be defined in a single message set.

When you deploy a message set to a broker, the definition of that message set is sent by the Configuration Manager to the broker in a form appropriate to the parser that is used to parse and write the message. The broker can manage multiple message dictionaries simultaneously.

For information about the benefits of predefining messages, see Why model messages?

The Video Rental sample and the Comma Separated Value (CSV) sample demonstrate how to model messages in XML, CWF, and TDS formats. The EDIFACT sample, FIX sample, SWIFT sample, and X12 sample provide message sets for industry-standard message formats, which might be useful if you use any of those formats. You can view samples only when you use the information center that is integrated with the Message Brokers Toolkit.

Self-defining messages

You can create and route messages that are self-defining. The best example of a self-defining message is an XML document.

Self-defining messages can also be modeled using the workbench. However, you do not have to deploy these message sets to the brokers that support those message flows. See Why model messages?.

The Large Messaging sample, the Airline Reservations sample, and several other samples in the Samples Gallery use self-defining XML messages for the sake of simplicity; they don't require a message set. The Coordinated Request Reply sample demonstrates how you can transform a message from self-defining XML to a predefined binary format, and the Data Warehouse sample demonstrates how you can extract information from an XML message and transform it into BLOB format to store it in a database. You can view samples only when you use the information center that is integrated with the Message Brokers Toolkit.

Related reference
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Last updated : 2009-01-07 15:19:56

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