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:
- Transforming data values from one or more attributes in a
source business object to one or more attributes in a destination
business object
- Establishing and maintaining relationships between data
entities that are equivalent but are represented differently and
cannot be directly transformed
- Enabling access to external mapping resources, such as
third-party mapping products and databases for performing
queries
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):
- 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.
- 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.
- The inbound map returns the
generic Employee business object to the App A
connector controller.
- 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.
- The collaboration performs some processing, then produces
another generic Employee business object as output, which
it sends to the App B connector controller.
- The App B connector controller sends the generic
business object to InterChange Server Express, requesting mapping
to the App B Employee business object.
- The outbound map returns
the application-specific Employee business object to the
App B connector controller.
- 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:
- One inbound map from the App A Employee business
object to the generic Employee business object used by the
collaboration
- One outbound map from the generic Employee business
object to the App B Employee business object
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:
- An inbound map from the application-specific business object of
Application B to the generic business object
- An outbound map from the generic business object to the
application-specific business object of Application A
