For the service integration logic, the integration developer creates
a specific type of component called a mediation flow component.
A mediation flow component contains one or more mediation primitives.
These are provided to control the flow of messages, rather than to perform
business functions.
The following standard mediation primitives are provided with WebSphere Integration Developer and WebSphere ESB.
MessageLogger
- The MessageLogger primitive logs a copy
of the message to a database for future retrieval or audit. The integration
developer can customize the primitive, for example by naming the database.
DatabaseLookup
- The DatabaseLookup primitive retrieves
values from a database and stores them in the message.
MessageFilter
- The MessageFilter primitive compares
the content of the message to expressions configured by the user, and routes
the message to the next mediation primitive based on the result.
XSLT
- The XSLT primitive transforms messages
according to transformations defined by an XSL style sheet.
Fail
- The Fail primitive throws an exception
and terminates the path through the mediation flow.
Stop
- And the Stop primitive silently terminates
the path through the mediation flow.
Each primitive has a Fail terminal so that if an error occurs, then messages
are sent to Fail and errors can be handled.
But if the supplied primitives do not meet the developer’s needs, a custom
mediation primitive can be used to author Java code, either directly or visually,
within an SCA Java component.