From Traditional Integration to Composition – Enterprise Business Services - Applied SOA Patterns on the Oracle Platform - page 252

Now, we have all the necessary functionalities to extract an execution plan. Similar to the
realization discussed in the previous chapter, the execution plans are the XML objects
stored as a file object, and they will be extracted from XML mapping file, linking the
sender and the message IDs with process. The name and location of this file is configured
using the web.xml deployment descriptor and extracted during the servlet's init phase.
The FileIO realization of this lookup makes this broker extremely lightweight and suitable
for autonomous installation on DMZ or in an integration zone without connecting to any
database. If your requirements are not that strict, you can implement Execu-
tionPlanLookupService as a WS (using SCA from the previous chapter) and in-
voke it using MessageHeader as an input parameter. This was not the case when we
decided to build this broker. After the extraction of the execution plan XML, we are ready
to process it.
Transform
Transformation is not the only task we will perform; therefore, this name is a bit mislead-
ing. In general, we can invoke any EJB or another HTTP endpoint registered in the execu-
tion plan. Initially, we agreed that the scope of our tasks will be transformation, transla-
tion, and delivery (as FileIO or HTTP post), which are presented as individual helpers
(dispatchers) that are controlled by the ProcessHandler factory. Please refer to the
following figure: