用spring整合xfire时传递自定义类型的对象时报空指针错误

Question

Exception in thread "main" org.codehaus.xfire.fault.XFireFault: Fault: java.lang.NullPointerException
at org.codehaus.xfire.fault.XFireFault.createFault(XFireFault.java:89)
at org.codehaus.xfire.client.Invocation.invoke(Invocation.java:83)
at org.codehaus.xfire.client.Invocation.invoke(Invocation.java:114)
at org.codehaus.xfire.client.Client.invoke(Client.java:336)
at org.codehaus.xfire.client.Client.invoke(Client.java:368)
at test.WebServiceClientTest.testClient(WebServiceClientTest.java:43)
at test.WebServiceClientTest.main(WebServiceClientTest.java:26)
Caused by: java.lang.NullPointerException
at org.codehaus.xfire.aegis.type.basic.ObjectType.writeObject(ObjectType.java:192)
at org.codehaus.xfire.aegis.AegisBindingProvider.writeParameter(AegisBindingProvider.java:229)
at org.codehaus.xfire.service.binding.AbstractBinding.writeParameter(AbstractBinding.java:273)
at org.codehaus.xfire.service.binding.WrappedBinding.writeMessage(WrappedBinding.java:90)
at org.codehaus.xfire.soap.SoapSerializer.writeMessage(SoapSerializer.java:80)
at org.codehaus.xfire.transport.http.HttpChannel.writeWithoutAttachments(HttpChannel.java:56)
at org.codehaus.xfire.transport.http.CommonsHttpMessageSender.getByteArrayRequestEntity(CommonsHttpMessageSender.java:422)
at org.codehaus.xfire.transport.http.CommonsHttpMessageSender.send(CommonsHttpMessageSender.java:360)
at org.codehaus.xfire.transport.http.HttpChannel.sendViaClient(HttpChannel.java:123)
at org.codehaus.xfire.transport.http.HttpChannel.send(HttpChannel.java:48)
at org.codehaus.xfire.handler.OutMessageSender.invoke(OutMessageSender.java:26)
at org.codehaus.xfire.handler.HandlerPipeline.invoke(HandlerPipeline.java:131)
at org.codehaus.xfire.client.Invocation.invoke(Invocation.java:79)
... 5 more