I haven't used soapUI for a while now and was surprised to see mock service functionality.
Mock Service (http://www.soapui.org/Service-Mocking/concept.html)
So first take the wsdl you have and generate a mock service using soap ui.
Create a new project: File Menu > Create new soapUI project.
Select the wsdl you will be working with.
Right click on the new Binding and select Generate MockService
Press ok twice.
Right click on the new Mock and select Start minimized.
You can create as many mock responses as you like and edit the xml response as you wish.
The xpath bit is the matching rules
The expected value is the value to match on in the incoming message
Last dropdown is the response you choose to return based on the above input
Important Soapy Example match
declare namespace v1='http://test.co.za/stuff/Messages/Test/V1';
declare namespace soapenv='http://schemas.xmlsoap.org/soap/envelope/';
Make sure the mock service is running.
Hook up to code
Now point your code (web service proxy pojo data control for me) to use the mock service url.
new TestService(new URL("http://127.0.0.1:8088/mockTestService", new QName("http://www.test.co.za/Test/V1","TestService")));
Run screen and test away.
I am using 4.5.0