About data mapping

Data mapping is the process of transforming (or mapping) data from one application-specific format to another. Mapping is central to the process of transferring information between different applications, and for providing collaborations (business processes) that are independent of specific applications. By mapping data between application-specific business objects and generic business objects, WebSphere creates the environment that allows for the use of "best of breed" applications. The WebSphere business integration system provides a modular and extensible architecture for easy maintenance of your maps.

The WebSphere map development system provides comprehensive support for mapping between business objects, including the following capabilities:

When data mapping is set up among differing applications, an event occurrence in one application is performed in any other application to which it is mapped. An event occurrence can be when data is created, retrieved, updated, or deleted.

Mapping uses maps that define the transfer (or transformation) of data between the source and destination business objects. In the map development environment, data is mapped from an application-specific business object to a generic business object or from a generic business object to an application-specific business object. Table 1 lists the types of mapping required.

Table 1. Mapping requirements

Direction of business object Source business object Destination business object Type of map
Connector to collaboration Application-specific Generic Inbound map
Collaboration to connector Generic Application-specific Outbound map

Figure 1 illustrates how mapping occurs at run time, using a fictionalized Employee Management collaboration as an example.

Figure 1. Data mapping at run time

The Employee Management collaboration (Collaboration1) receives an Employee business object from the source connector (App A), then sends an Employee business object to the destination connector (App B). Figure 1 illustrates the following sequence occurs (the numbers here correspond to the numbers in the figure):

  1. An event occurs in App A. The App A connector produces an App A Employee business object and sends it to the App A connector controller.
  2. The App A connector controller sends the App A Employee business object to the Employee Management collaboration (Collaboration1), which resides on InterChange Server Express, for mapping. The request includes the name of the data map that the server must use, based on the map name specified in the connector configuration.
  3. The inbound map returns the generic Employee business object to the App A connector controller.
  4. The App A connector controller checks the collaborations that have subscriptions to the generic Employee business object. In this case, Collaboration1 has a subscription, so the connector controller hands the business object to Collaboration1.
  5. The collaboration performs some processing, then produces another generic Employee business object as output, which it sends to the App B connector controller.
  6. The App B connector controller sends the generic business object to InterChange Server Express, requesting mapping to the App B Employee business object.
  7. The outbound map returns the application-specific Employee business object to the App B connector controller.
  8. The App B connector controller passes the App B Employee object to the App B connector, which can then pass the data in the business object into App B.

The figure shows two types of maps in use:

The Employee data moves in only one direction--from Application A toward Application B. If you want to exchange the Employee data in both directions between both applications, two more maps are required:

Copyright IBM Corp. 2003