★★★★★如何在单点登录环境下使用Web服务？★★★★★

工具： 
SSO框架：CAS 
WS框架：CXF 
IoC框架：Spring 场景：
两个应用，在同一个Tomcat下，APP1调用APP2 
通过Spring整合CAS，并且CAS已与LDAP集成 问题：
若不开启CAS服务器，则WS调用正常； 
若开启了CAS服务器，则WS调用失败，报错现象如下： 11:05:20,015 ERROR com.company.eproject.controller.EngineeringController (238) -
 javax.xml.ws.soap.SOAPFaultException: Error reading XMLStreamReader. 
at org.apache.cxf.jaxws.JaxWsClientProxy.invoke(JaxWsClientProxy.java:146) 
at $Proxy48.getUserList(Unknown Source) 
at com.company.eproject.controller.EngineeringController.loadDetail(EngineeringController.java:230)
 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 org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176)
 at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:426)
 at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:414)
 at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790)
 at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
 at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644)
 at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:549)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:621) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722) 
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
 at org.jasig.cas.client.util.AssertionThreadLocalFilter.doFilter(AssertionThreadLocalFilter.java:54)
 at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
 at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
 at org.jasig.cas.client.util.HttpServletRequestWrapperFilter.doFilter(HttpServletRequestWrapperFilter.java:75)
 at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
 at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
 at org.jasig.cas.client.validation.AbstractTicketValidationFilter.doFilter(AbstractTicketValidationFilter.java:197)
 at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
 at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
 at org.jasig.cas.client.authentication.AuthenticationFilter.doFilter(AuthenticationFilter.java:107)
 at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
 at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
 at org.jasig.cas.client.session.SingleSignOutFilter.doFilter(SingleSignOutFilter.java:76)
 at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
 at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
 at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
 at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
 at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
 at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
 at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
 at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562) 
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395) 
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250) 
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
 at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
 at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
 at java.lang.Thread.run(Thread.java:662) 
Caused by: javax.xml.stream.XMLStreamException: ParseError at [row,col]:[1,1] 
Message: Premature end of file. 
at com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next(XMLStreamReaderImpl.java:594)
 at com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.nextTag(XMLStreamReaderImpl.java:1235)
 at org.apache.cxf.binding.soap.interceptor.ReadHeadersInterceptor.handleMessage(ReadHeadersInterceptor.java:138)
 at org.apache.cxf.binding.soap.interceptor.ReadHeadersInterceptor.handleMessage(ReadHeadersInterceptor.java:60)
 at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:263)
 at org.apache.cxf.endpoint.ClientImpl.onMessage(ClientImpl.java:736) 
at org.apache.cxf.transport.http.HTTPConduit$WrappedOutputStream.handleResponseInternal(HTTPConduit.java:1563)
 at org.apache.cxf.transport.http.HTTPConduit$WrappedOutputStream.handleResponse(HTTPConduit.java:1448)
 at org.apache.cxf.transport.http.HTTPConduit$WrappedOutputStream.close(HTTPConduit.java:1356)
 at org.apache.cxf.transport.AbstractConduit.close(AbstractConduit.java:56) 
at org.apache.cxf.transport.http.HTTPConduit.close(HTTPConduit.java:614) 
at org.apache.cxf.interceptor.MessageSenderInterceptor$MessageSenderEndingInterceptor.handleMessage(MessageSenderInterceptor.java:62)
 at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:263)
 at org.apache.cxf.endpoint.ClientImpl.doInvoke(ClientImpl.java:484) 
at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:414) 
at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:317) 
at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:269) 
at org.apache.cxf.frontend.ClientProxy.invokeSync(ClientProxy.java:73) 
at org.apache.cxf.jaxws.JaxWsClientProxy.invoke(JaxWsClientProxy.java:124) 
... 62 more我用SoapUI无法检测到结果，本来调用WS的URL是： 
http://tomcat:8081/user/services/UserService 但这个请求会被CAS客户端过滤器给拦截住，并发送到CAS服务器。 
此后，CAS服务器会改变这个URL，并再次调用User组件发布的WS。 我觉得是不是需要在CAS上进行Proxy设置，才能解决这个问题？ 不知道此问题，是否有人曾经遇到并解决过？