我有一段代码，使用dom4j 正则表达式解析gml ， 代码如下：
ListfeatureMembers= root.selectNodes("featureMember");
发生以下异常：
java.lang.NoClassDefFoundError: org/jaxen/JaxenException at org.dom4j.DocumentFactory.createXPath(DocumentFactory.java:230) at org.dom4j.tree.AbstractNode.createXPath(AbstractNode.java:207) at org.dom4j.tree.AbstractNode.selectNodes(AbstractNode.java:164) at com.geoway.spatial.util.LocationUtils.parseTDTResponseDocument(LocationUtils.java:56) at com.geoway.spatial.util.LocationUtils.queryTDTWFS(LocationUtils.java:33) at com.geoway.spatial.service.impl.TDTLocationServiceImpl.getLocationByName(TDTLocationServiceImpl.java:28) at com.geoway.spatial.service.impl.LocationAdapter.getLocationByName(LocationAdapter.java:31) at com.geoway.spatial.service.impl.LocationAdapter.test(LocationAdapter.java:48) 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.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:297) at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:250) at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:144) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:350) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1329) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:471) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409) at java.security.AccessController.doPrivileged(Native Method) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:217) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:429) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:729) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:381) at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:255) at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:199) at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:45) at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3934) at org.apache.catalina.core.StandardContext.start(StandardContext.java:4429) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:526) at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:987) at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:909) at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:495) at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1206) at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:314) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053) at org.apache.catalina.core.StandardHost.start(StandardHost.java:722) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045) at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443) at org.apache.catalina.core.StandardService.start(StandardService.java:516) at org.apache.catalina.core.StandardServer.start(StandardServer.java:710) at org.apache.catalina.startup.Catalina.start(Catalina.java:583) 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.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)Caused by: java.lang.ClassNotFoundException: org.jaxen.JaxenException at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1387) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1233) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320) ... 56 more
根据异常，发现少了一个类：org.jaxen.JaxenException 这个类存在jaxen.jar包中，原因可想而知了！在路径下加入这个jar包即可。