That's just a hypothetical service that "does something" with the email. In the example on page 189, the emailHandlingService might have a method
Code:
public Foo handleEmail(String email) {...}
In the example on page 190, the custom transformer might transform the 'javax.mail.Message' to a Bar object, in which case, the method might look like
Code:
public Foo handleTransformedEmail(Bar bar) {...}
Bottom line is you can do whatever you want with the results of the transformation.
You are not required to use the transformer either, the service method can simply take a 'javax.mail.Message' and act on it directly.
The service method can even return 'void' if it's the end of the flow.
Last edited by Gary Russell; Dec 2nd, 2012 at 04:06 PM.
Gary P. Russell
Spring Integration Team
SpringSource, a division of VMware