深入dom4j使用selectSingleNode方法报错分析

我有一段代码，使用dom4j 正则表达式解析gml ， 代码如下：
List<Element> featureMembers= 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。