用JAX-WS框架搭的WebService时出现了问题,求高手解决

    我在2个系统中用JAX-WS框架搭的WebService时出现了问题，错误提示如下，搞了我整个下午也不得其解，请各位高手帮忙解决一下，谢谢！
2010-9-15 20:16:28 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet UserLoginServlet threw exception
com.sun.xml.ws.encoding.soap.DeserializationException: Failed to read a response: javax.xml.bind.UnmarshalException
 - with linked exception:
[javax.xml.stream.XMLStreamException: ParseError at [row,col]:[1,203]
Message: An invalid XML character (Unicode: 0x0) was found in the element content of the document.]
at com.sun.xml.ws.client.sei.SyncMethodHandler.invoke(SyncMethodHandler.java:124)
at com.sun.xml.ws.client.sei.SyncMethodHandler.invoke(SyncMethodHandler.java:89)
at com.sun.xml.ws.client.sei.SEIStub.invoke(SEIStub.java:118)
at $Proxy86.getUserByUserName(Unknown Source)
at com.biz.impl.IUsersBizImpl.getUserByUserName(IUsersBizImpl.java:68)
at com.servlet.UserLoginServlet.service(UserLoginServlet.java:44)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.filter.ProgramFilter.doFilter(ProgramFilter.java:33)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:228)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:216)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:634)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:445)
at java.lang.Thread.run(Unknown Source)
Caused by: javax.xml.bind.UnmarshalException
 - with linked exception:
[javax.xml.stream.XMLStreamException: ParseError at [row,col]:[1,203]
Message: An invalid XML character (Unicode: 0x0) was found in the element content of the document.]
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.handleStreamException(UnmarshallerImpl.java:422)
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:360)
at com.sun.xml.bind.v2.runtime.BridgeImpl.unmarshal(BridgeImpl.java:120)
at com.sun.xml.bind.api.Bridge.unmarshal(Bridge.java:233)
at com.sun.xml.ws.client.sei.ResponseBuilder$DocLit.readResponse(ResponseBuilder.java:525)
at com.sun.xml.ws.client.sei.SyncMethodHandler.invoke(SyncMethodHandler.java:121)
... 21 more
Caused by: javax.xml.stream.XMLStreamException: ParseError at [row,col]:[1,203]
Message: An invalid XML character (Unicode: 0x0) was found in the element content of the document.
at com.sun.xml.stream.XMLReaderImpl.next(XMLReaderImpl.java:563)
at com.sun.xml.ws.util.xml.XMLStreamReaderFilter.next(XMLStreamReaderFilter.java:92)
at com.sun.xml.bind.v2.runtime.unmarshaller.StAXStreamConnector.bridge(StAXStreamConnector.java:225)
at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:358)
... 25 more