Web Services structure of input and output

Is it necessary that the structure of input and output of a web service be embedded within the wsdl ?

Say for example i have a method that accepts a String input and returns a String output - c开发者_高级运维an't that be exposed as a service with the input and output adhering to specific structures? In this case the wsdl does not necessarily represent the actual/complete structure of the input or output. Would the API so exposed not qualify to be called a web service? Or is it just that it is not the standard way for exposing a service?

If you want your web service to comply with WS-I, and be able to interoperate, the answer is 'yes'. if the WSDL doesn't describe the service, things won't be able to call it.

If you don't want your web service to comply with WS-I and be able to interoperate via that mechanism, you can do whatever you want. You might, for example, choose to use a REST style.

In other words, 'web service' is not a very specific term. You need to be much more specific in defining your requirements. Some situations require services accurately described by a WSDL, and some don't.