Java List to Scala Conversion Error - scala

Question

I have a Java code base that returns me a java.util.List that I consume in my Scala layer as below:
import scala.collection.JavaConverters._
val myList = myServiceClient.getMyList.asScala.toList //fails here!
println(myList)
I then hit the following error:
Exception in thread "main" javax.xml.ws.soap.SOAPFaultException: scala.collection.immutable.$colon$colon cannot be cast to java.util.List
at org.apache.cxf.jaxws.JaxWsClientProxy.invoke(JaxWsClientProxy.java:161)
at com.sun.proxy.$Proxy49.getSlaveList(Unknown Source)
at Test$.main(Test.scala:35)
at Test.main(Test.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)
Caused by: java.lang.ClassCastException: scala.collection.immutable.$colon$colon cannot be cast to java.util.List
at org.apache.cxf.binding.soap.SoapMessage.getHeaders(SoapMessage.java:56)
at org.apache.cxf.binding.soap.interceptor.SoapHeaderOutFilterInterceptor.handleMessage(SoapHeaderOutFilterInterceptor.java:37)
at org.apache.cxf.binding.soap.interceptor.SoapHeaderOutFilterInterceptor.handleMessage(SoapHeaderOutFilterInterceptor.java:29)
at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:308)
at org.apache.cxf.endpoint.ClientImpl.doInvoke(ClientImpl.java:514)
at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:423)
at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:324)
at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:277)
at org.apache.cxf.frontend.ClientProxy.invokeSync(ClientProxy.java:96)
at org.apache.cxf.jaxws.JaxWsClientProxy.invoke(JaxWsClientProxy.java:139)
... 8 more

Answer 1

So the original problem was a couple of lines above in my code base to what I posted in my original question:
I had to do the following when I pass the List to the Apache CXF library:
val headerList = Seq(
new Header(new QName("http://www.myService.com/MyServices/", "UserName"), "", new JAXBDataBinding(classOf[String])),
new Header(new QName("http://www.myService.com/MyServices//", "Password"), "", new JAXBDataBinding(classOf[String]))
)
import scala.collection.JavaConverters._
proxy.getRequestContext.put(Header.HEADER_LIST, headerList.asJava)