The Service Interface— Contract
Every SOA service interaction involves some form of consumer request and usually an exchange of information. Consumers will send a request and specify a service operation, and the service will resolve that request. The Message Exchange Patterns (MEPs) can vary from request-reply to an asynchronous fire-and-forget, but the interaction and exchange of information is constant. The consumer request is expressed in the body of a request message, and the service response is expressed in a reply message (assuming a request-reply MEP). In either case, the content of the message is described as “data in motion” and must be structured according to the service interface definition.
Ensuring that these service collaborators ...