当我从Web服务调用EWS Java API时，出现错误。
完整的堆栈跟踪如下。
仅供参考，com.ixbat.synchroexchangews是我们的网络服务。它调用JAR（synchroexchange。*），它调用EWS API。
是否可以从其他Web服务调用EWS API？ 为什么会出现这种错误？
microsoft.exchange.webservices.data.core.exception.service.remote.ServiceRequestException: The request failed. null
at microsoft.exchange.webservices.data.core.request.SimpleServiceRequestBase.internalExecute(SimpleServiceRequestBase.java:74)
at microsoft.exchange.webservices.data.core.request.MultiResponseServiceRequest.execute(MultiResponseServiceRequest.java:158)
at microsoft.exchange.webservices.data.core.ExchangeService.internalCreateItems(ExchangeService.java:598)
at microsoft.exchange.webservices.data.core.ExchangeService.createItem(ExchangeService.java:657)
at microsoft.exchange.webservices.data.core.service.item.Item.internalCreate(Item.java:245)
at microsoft.exchange.webservices.data.core.service.item.Item.save(Item.java:386)
at synchroexchange.ExtendedTask.create(ExtendedTask.java:108)
at synchroexchange.ExchangeManager.wsPropagerAction(ExchangeManager.java:734)
at synchroexchange.ExchangeManager.wsPropagerAction(ExchangeManager.java:702)
at com.ixbat.synchroexchangews.SynchroExchangews.propagerAction(SynchroExchangews.java:152)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at weblogic.wsee.jaxws.WLSInstanceResolver$WLSInvoker.invoke(WLSInstanceResolver.java:117)
at weblogic.wsee.jaxws.WLSInstanceResolver$WLSInvoker.invoke(WLSInstanceResolver.java:91)
at com.sun.xml.ws.server.InvokerTube$2.invoke(InvokerTube.java:149)
at com.sun.xml.ws.server.sei.SEIInvokerTube.processRequest(SEIInvokerTube.java:88)
at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:1136)
at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:1050)
at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:1019)
at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:877)
at com.sun.xml.ws.server.WSEndpointImpl$2.process(WSEndpointImpl.java:419)
at com.sun.xml.ws.transport.http.HttpAdapter$HttpToolkit.handle(HttpAdapter.java:868)
at com.sun.xml.ws.transport.http.HttpAdapter.handle(HttpAdapter.java:422)
at com.sun.xml.ws.transport.http.servlet.ServletAdapter.handle(ServletAdapter.java:169)
at weblogic.wsee.jaxws.WLSServletAdapter.handle(WLSServletAdapter.java:199)
at weblogic.wsee.jaxws.HttpServletAdapter$AuthorizedInvoke.run(HttpServletAdapter.java:640)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:363)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:146)
at weblogic.wsee.util.ServerSecurityHelper.authenticatedInvoke(ServerSecurityHelper.java:108)
at weblogic.wsee.jaxws.HttpServletAdapter$3.run(HttpServletAdapter.java:284)
at weblogic.wsee.jaxws.HttpServletAdapter.post(HttpServletAdapter.java:293)
at weblogic.wsee.jaxws.JAXWSServlet.doRequest(JAXWSServlet.java:128)
at weblogic.servlet.http.AbstractAsyncServlet.service(AbstractAsyncServlet.java:99)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:844)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:280)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:254)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:136)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:346)
at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:25)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)
at oracle.security.jps.ee.http.JpsAbsFilter$1.run(JpsAbsFilter.java:137)
at java.security.AccessController.doPrivileged(Native Method)
at oracle.security.jps.util.JpsSubject.doAsPrivileged(JpsSubject.java:315)
at oracle.security.jps.ee.util.JpsPlatformUtil.runJaasMode(JpsPlatformUtil.java:460)
at oracle.security.jps.ee.http.JpsAbsFilter.runJaasMode(JpsAbsFilter.java:120)
at oracle.security.jps.ee.http.JpsAbsFilter.doFilter(JpsAbsFilter.java:217)
at oracle.security.jps.ee.http.JpsFilter.doFilter(JpsFilter.java:81)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)
at oracle.dms.servlet.DMSServletFilter.doFilter(DMSServletFilter.java:220)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3436)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3402)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
at weblogic.servlet.provider.WlsSubjectHandle.run(WlsSubjectHandle.java:57)
at weblogic.servlet.internal.WebAppServletContext.doSecuredExecute(WebAppServletContext.java:2285)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2201)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2179)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1572)
at weblogic.servlet.provider.ContainerSupportProviderImpl$WlsRequestExecutor.run(ContainerSupportProviderImpl.java:255)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:311)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:263)
Caused by: java.lang.NullPointerException
at com.ctc.wstx.sw.BaseStreamWriter.writeCharacters(BaseStreamWriter.java:451)
at microsoft.exchange.webservices.data.core.EwsServiceXmlWriter.writeValue(EwsServiceXmlWriter.java:307)
at microsoft.exchange.webservices.data.property.complex.StringList.writeElementsToXml(StringList.java:117)
at microsoft.exchange.webservices.data.property.complex.ComplexProperty.writeToXml(ComplexProperty.java:325)
at microsoft.exchange.webservices.data.property.complex.ComplexProperty.writeToXml(ComplexProperty.java:338)
at microsoft.exchange.webservices.data.property.definition.ComplexPropertyDefinitionBase.writePropertyValueToXml(ComplexPropertyDefinitionBase.java:170)
at microsoft.exchange.webservices.data.core.PropertyBag.writeToXml(PropertyBag.java:548)
at microsoft.exchange.webservices.data.core.service.ServiceObject.writeToXml(ServiceObject.java:321)
at microsoft.exchange.webservices.data.core.request.CreateRequest.writeElementsToXml(CreateRequest.java:129)
at microsoft.exchange.webservices.data.core.request.ServiceRequestBase.writeBodyToXml(ServiceRequestBase.java:134)
at microsoft.exchange.webservices.data.core.request.ServiceRequestBase.writeToXml(ServiceRequestBase.java:256)
at microsoft.exchange.webservices.data.core.request.ServiceRequestBase.buildEwsHttpWebRequest(ServiceRequestBase.java:696)
at microsoft.exchange.webservices.data.core.request.ServiceRequestBase.buildEwsHttpWebRequest(ServiceRequestBase.java:665)
at microsoft.exchange.webservices.data.core.request.ServiceRequestBase.validateAndEmitRequest(ServiceRequestBase.java:635)
at microsoft.exchange.webservices.data.core.request.SimpleServiceRequestBase.internalExecute(SimpleServiceRequestBase.java:62)
... 63 more
感谢您的帮助
答案 0 :(得分：1)
在没有看到实际代码的情况下，我无法确定，但我会根据您向Web服务发送请求的堆栈跟踪进行推测，但是当它正在编组XML时，其中一个字段是null，所以它抛出了这个异常。我鼓励你调试并弄清楚你试图发送的任何字段是否实际上是丢失的。