Using the File JCA adapter to read a file within the message flow

If there is a need to read the contents of a file inside a message flow of an already active proxy service, then neither the File Transport nor the FTP transport can be of any help. Reading a file with the File or FTP Transport is always only available inbound, implemented as a polling operation and starting a new message flow/proxy service upon detecting a new file.

This recipe will show how we can use the File JCA adapter to read a file at runtime, for example, to enrich data at runtime or to retrieve some configuration information. The JCA adapters are available since OSB 11g and are the same ones we know from the SOA Suite.

We will create a business service wrapping the artifacts created by the JCA adapter wizard in JDeveloper. By that the business service is just as any other business service seen so far and can be invoked from a proxy service using a Routing or Service Callout action as shown in this recipe.

The scenario...