Interface is not visible from class loader

I'm new to play! framework and using wsdl2java tools. I'm developing a play! application that needs to interact with a SOAP webservice. I have the WSDL and created objects from it using jaxws. It's creating a bunch of java classes and 1 interface. As soon as I try to make a webservice call, I get an error that the interface cannot be found by the classloader. This is my code:

MyWebserviceBeanService service = new MyWebserviceBeanService();
MyWebserviceRemote mwr = service.getMyWebserviceBeanPort();
LoginResponse response = mwr.loginUser("xxx", "xxx");

Notice that 'MyWebserviceRemote' is the interface. The code of getMyWebserviceBeanPort is quite common as it is generated automatically, but here it is:

@WebEndpoint(name = "MyWebserviceBeanPort")
public MyWebserviceRemote getMyWebserviceBeanPort() {
    return super.getPort(new QName("http://xxxxxxxxxx/", "MyWebserviceBeanPort"), MyWebserviceRemote.class);
}

When I try to call a method, e.g. the loginUser method as above, I get the following stacktrace:

play.exceptions.JavaExecutionException: interface xxxx.xxxx.xxxx.MyWebserviceRemote is not visible from class loader
    at play.mvc.ActionInvoker.invoke(ActionInvoker.java:237)
    at Invocation.HTTP Request(Play!)
Caused by: java.lang.IllegalArgumentException: interface xxxx.xxxxx.xxxx.MyWebserviceRemote is not visible from class loader
    at com.sun.xml.ws.client.WSServiceDelegate.createEndpointIFBaseProxy(WSServiceDelegate.java:736)
    at com.sun.xml.ws.client.WSServiceDelegate.getPort(WSServiceDelegate.java:408)
    at com.sun.xml.ws.client.WSServiceDelegate.getPort(WSServiceDelegate.java:384)
    at com.sun.xml.ws.client.WSServiceDelegate.getPort(WSServiceDelegate.java:366)
    at javax.xml.ws.Service.getPort(Service.java:119)
    at xxxx.xxxx.xxxx.MyWebserviceBeanService.getMyWebserviceBeanPort(MyWebserviceBeanService.java:72)
    at controllers.MyController.index(MyController.java:26)
    at play.mvc.ActionInvoker.invokeWithContinuation(ActionInvoker.java:557)
    at play.mvc.ActionInvoker.invoke(ActionInvoker.java:508)
    at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:484)
    at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:479)
    at play.mvc.ActionInvoker.invoke(ActionInvoker.java:161)
    ... 1 more

I have really no idea how to fix this, or even how to debug this. Where do I look? Where do I start? I tested the webservice using SoapUI and it works fine.

Thanks!

Solution

This was caused by conflicting jar files in the play framework (3 jars in total with 'jax' in the name). I removed them and all is well now. Hurray for descriptive error messages :-)