javax.xml.stream.FactoryFinder$ConfigurationError: Provider com.ctc.wstx.stax.WstxInputFactory not found

I am trying to develop a GWT application that calls an existing (working) web service. I am using:

      - JAX-WS RI 2.1.6 in JDK 6
      - JDK 6
      - Glassfish V3
      - Eclipse 20110615-0604

I have tested my 3 component applications independently and they work fine:

1. GWT application - browser invoking GWT server side code. This is based on the GWT sample, http://code.google.com/webtoolkit/gettingstarted.html#create
2. Java application that uses JAX-WS proxy to invoke a Web Service. This is based on a JAX-WS hello world sample. I used wsimport on my wsdl to generate the proxy code.
3. Pre-existing Web Service, which I have the WSDL for.

When I merge the top 2 pieces of code, to create a GWT application that calls a web service from within the GWT server side code, my merged application fails with the exception below. I suspect some class conflict between the standard GWT dependencies and the standard JAX-WS dependencies.

I get the following exception:

javax.servlet.ServletContext log: Exception while dispatching incoming RPC call com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract java.lang.String com.mjg.training.client.GreetingService.greetServer(java.lang.String) throws java.lang.IllegalArgumentException' threw an unexpected exception: javax.xml.stream.FactoryFinder$ConfigurationError: Provider com.ctc.wstx.stax.WstxInputFactory not found at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:385) at com.google.gwt.user.server.rpc.R开发者_如何学PythonPC.invokeAndEncodeResponse(RPC.java:588) at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208) at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248) at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62) at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166) at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:35) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:58) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:122) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:97) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388) at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216) at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765) at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418) at com.google.apphosting.utils.jetty.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:70) at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:351) at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) at org.mortbay.jetty.Server.handle(Server.java:326) at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542) at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938) at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755) at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218) at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404) at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409) at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582) Caused by: javax.xml.stream.FactoryFinder$ConfigurationError: Provider com.ctc.wstx.stax.WstxInputFactory not found at javax.xml.stream.FactoryFinder.newInstance(FactoryFinder.java:154) at javax.xml.stream.FactoryFinder.findJarServiceProvider(FactoryFinder.java:308) at javax.xml.stream.FactoryFinder.find(FactoryFinder.java:233) at javax.xml.stream.XMLInputFactory.newInstance(XMLInputFactory.java:123) at com.sun.xml.internal.ws.api.streaming.XMLStreamReaderFactory.getXMLInputFactory(XMLStreamReaderFactory.java:98) at com.sun.xml.internal.ws.api.streaming.XMLStreamReaderFactory.(XMLStreamReaderFactory.java:67) at com.sun.xml.internal.ws.wsdl.parser.RuntimeWSDLParser.createReader(RuntimeWSDLParser.java:794) at com.sun.xml.internal.ws.wsdl.parser.RuntimeWSDLParser.resolveWSDL(RuntimeWSDLParser.java:251) at com.sun.xml.internal.ws.wsdl.parser.RuntimeWSDLParser.parse(RuntimeWSDLParser.java:118) at com.sun.xml.internal.ws.client.WSServiceDelegate.parseWSDL(WSServiceDelegate.java:254) at com.sun.xml.internal.ws.client.WSServiceDelegate.(WSServiceDelegate.java:217) at com.sun.xml.internal.ws.client.WSServiceDelegate.(WSServiceDelegate.java:165) at com.sun.xml.internal.ws.spi.ProviderImpl.createServiceDelegate(ProviderImpl.java:93) at javax.xml.ws.Service.(Service.java:56) at amx.devenvironment.helloworld1.JavaHelloComponent100201106212354ServiceHelloWorldPTHelloWorldPT.(JavaHelloComponent100201106212354ServiceHelloWorldPTHelloWorldPT.java:46) at sample.HelloWorldGetResponse.getResponse(HelloWorldGetResponse.java:16) at com.mjg.training.server.GreetingServiceImpl.greetServer(GreetingServiceImpl.java:46) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:100) at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:569)

Earlier I was getting this exception:

[ERROR] javax.servlet.ServletContext log: Exception while dispatching incoming RPC call com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract java.lang.String com.mjg.training.client.GreetingService.greetServer(java.lang.String) throws java.lang.IllegalArgumentException' threw an unexpected exception: javax.xml.transform.TransformerFactoryConfigurationError: Provider org.apache.xalan.processor.TransformerFactoryImpl not found
    at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:385)
    at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:588)

I solved that by adding these lines to my code:

System.setProperty("javax.xml.transform.TransformerFactory","com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl");

Is there some other similar work around for the first exception.

Thanks, Matt.