®
IBM Software Group
Using Rational Software Architect to Drive
Application Integration Message Definition from
Information Models using a Model-Driven
Development Approach
Mariangela Orme
Executive IT/Architect
IBM Rational Services
[email protected]
CIM User Group 2010 - Milan
© 2004 IBM Corporation
IBM Software Group
Problem Statement
In many industries, there is a growing trend to standardize on
information being passed between systems themselves and
systems and client applications. Various standards bodies
comprised of corporate industry leaders are attempting to define
common data that is to be used as a basis for interoperability. In
some situations, messages themselves are defined as part of the
standard. In most cases an information model is provided as a
basis for messaging data. It is often necessary to create new
message definitions based on the standard information model.
Therefore, tooling is needed to help create standards-based
message definitions.
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Goal
The ultimate result of this strategy is to
show that Rational Software Architect
can be used as a single tool platform
for the creation, maintenance and
governance of industry information
model-based message definitions and
the implementation code needed to
process the message data.
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The Rational Software Architect Solution
 The following principles apply to the proposed strategy
1. A cursory examination of information models across different industries shows that
the models are in various states of maturity. Also, there are various levels of detail in
the models with respect to “closeness to implementation”. For example, some
information models simply are interested in showing abstraction relationships but do
little to further specify that relationship (direction, multiplicity, etc.).
Therefore, there will be a need to augment the model and further specify its contents.
However, it is still important to maintain some compliance to the original
standard no matter how far from your reality it is.
2. Tooling should be established to help the user maintain and manage their extended
information model.
3. It is assumed that the user has a desire to propose changes back to the standards
body. Therefore, tooling should help with this effort.
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The Rational Software Architect Solution
4. There is a conflict in principles between a well formed and normalized data types
model (information model) and a messaging strategy that attempts to limit the
message payload and the computing resources necessary to process the messages.
Therefore a strategy needs to be put in place to allow for the ability to subset the
information model. A typical information model used in its pure form for even the
simplest of messages would contain tens if not hundreds of types to fully satisfy the
enclosure, even if most of the data were optional. A mechanism needs to be
provided that allows the user to maintain the integrity of the information model
abstractions yet be able to only take the subset of those abstractions needed to
satisfy a particular message scenario. It could be debated whether you can then call
these resulting messages “compliant” to the standard, yet the reasons for doing so
are still valid.
- Categories
- Relationships
- Normalization
vs.
- Light payload
- Simpler implementation
- De-normalization
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The Rational Software Architect Solution
5. A model-driven approach is also desired that allows you to model your message
definitions and have them auto-generated by a model transformation. The reverse is
also true in that the ability to reverse transform an existing data definition into a UML
model is desirable since some standards bodies publish data definitions (xsd) as part
of its content. It is therefore desirable to see what those definitions look like in UML.
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The Rational Software Architect Solution
 The following principles apply to the proposed strategy (continued)
6. Once you have established your desired data definitions and messages, there is the
obvious task of building any necessary implementation components necessary
realize the interoperability. There are numerous options here and many off-the-shelf
solutions that provide large-scale solutions.
•
Enterprise Service Bus solutions such as WebSphere Message Broker or
WebSphere ESB
•
Process choreography solutions such as WebSphere Process Server
•
Web Service implementations
The data and message definitions as defined by the resulting XSDs can be directly
imported into such solutions.
7. Tooling should also be provided to allow a more custom implementation approach,
such as building java implementations of web services, the creation of XML data
manipulation code via JAXB, or the creation of XSL translations to mediate between
data definitions.
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Use Case Model
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Maintain Information Model Use Case
Pre-conditions: An information model in RSA format
1. Import the information model into RSA
2. Create a diff report to determine what is new with the latest version of the
model. Compare it to the previous version as well as your extensions to
determine if anything you added is now part of the standard model.
3. Extend the information as necessary. As you work on the model, the tool
needs to prevent you from making changes to the model structure. The tool
also needs to automatically mark the model to be able to visually see the
additions you have made to the model.
4. Create a report that shows the additions that you have made to the model.
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Maintain Information Model Use Case
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Maintain Message/Service Model Use Case
Pre-conditions: An extended information model
1. For a particular message scenario, examine the extended information model
for the data types that are deemed necessary. Utilize the RSA Browse
diagram feature to understand the enclosure scope of any given information
data type (UML class)
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Maintain Message/Service Model Use Case
2. Mark the primary data types in the information model that are necessary to
satisfy the message scenario with either a <<Select>> or <<SelectAll>>
stereotype. <<SelectAll>> for a class/enumeration indicates that the class
and all of its attributes are included. A <<Select>> stereotype for a class
simply includes the class itself. You must subsequently provide the
<<Select>> stereotype to individual properties for them to be included.
3. Once you have determined the necessary primary data types, execute the
transformation that will extract the selected data types into a separate model.
If it is determined that more data types are necessary, repeat steps 2 and 3
accordingly.
For each selected class the transformation will bring over the class and its
one level closure. I believe this to be a good solution in that it does not force
you to have to truly select every class you want yet it doesn’t bring the entire
enclosure over either.
The resulting model then represents the information model abstractions that
are deemed necessary for the message scenario.
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4. In order to save the <<Select>> and <<SelectAll>> markings that have
captured the chosen abstractions for a message scenario, execute an action
that will save these selections to an xml file. This is important for two
reasons. One you most likely will have many different message scenarios
that will have different information model selections. This allows you to save
numerous xml files with different selection criteria. Secondly, when a new
version of the information model is brought into use, you will want to be able
to restore these selections to the new version.
5. The model that results from the transformation now includes just the
information model classes that are necessary for the message scenario. The
model can now be manipulated to produce the necessary message and
service constructs. Manipulation includes severing relationships to limit
complexity. This model is completely editable yet care should be taken to
preserve the integrity of the standard types. You will need to add the XSD
and SoaML profiles as well as the XSDDataTypes model library to the model.
This gives you the necessary stereotypes you need to execute the UML to
XSD and UML to WSDL transformations.
6. Generate the XSDs and WSDLs by executing the UML to XSD and/or UML to
WSDL transformations.
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Maintain Message/Service Model Use Case
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Develop Integration Implementation Use Case
Pre-conditions: XSDs and WSDLs
1. Utilize automation tools such as:
1. Generating JAXB code to process the XSDs
2. Using model mapping to map data between to XSDs (or XML or DTD) to
automatically create a XSLT transformation file. Then auto-generate the
necessary XSLT implementation.
3. Create web service implementations and clients from WSDLs
2. Import XSDs and WSDLs into middleware development tools (WebSphere
Integration Developer, WebSphere Message Broker, WebSphere ESB, etc.)
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Develop Integration Implementation Use Case
XML Development tooling
 XML editor and validator
 XSL schema editor and validator
 Simplified XML schema graphical editing options
 High performance XML schema validator
 XML schema document generator
 XML schema inference (XML -> XSD)
 XML grammar converters (DTD -> XSD, XSD -> DTD)
 XML schema to Java code generation (XSD -> Java via JAXB – JSR222)
 DTD editor and validator
 XSLT editor and validator
 XSLT debugger
 XPath wizard
 XML-to-XML mapper (also utilizes XSD and DTD as input)
 XSLT implementation generator
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Develop Integration Implementation Use Case
Web Service tooling
 Web Services wizards to take you through each step in Web Service
development
 Generate Web Service client from WSDL/WSIL
 Create Web Services from Java Beans or WSDL/WSIL files using Axis 1.3
Web service runtime
 WSDL visual editor
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Maintain Message/Service Model Use Case
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