When you create a REST Web Service Consumer transformation, you select the HTTP method and define the method input and output. If you select the Get method, you do not define method input.
The input elements in the HTTP request message map to input ports. The output elements in the HTTP response message map to output ports. The Developer tool creates ports for the first level elements.
When you configure the transformation, you complete the following tasks:
Select the HTTP method.
Configure ports to represent elements in the header and body of the request and response messages.
Configure the input mapping.
Configure the output mapping.
Configure advanced properties such as the connection and the base URL for the web service.
If the REST web service requires authentication, create an HTTP connection object.