我配置了一下，出了以下错误 不知道为什么，请高手指教！
严重: Dispatcher initialization failed
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at com.opensymphony.xwork2.inject.ContainerImpl$MethodInjector.inject(ContainerImpl.java:295)
at com.opensymphony.xwork2.inject.ContainerImpl$ConstructorInjector.construct(ContainerImpl.java:431)
at com.opensymphony.xwork2.inject.ContainerBuilder$5.create(ContainerBuilder.java:207)
at com.opensymphony.xwork2.inject.Scope$2$1.create(Scope.java:51)
at com.opensymphony.xwork2.inject.ContainerBuilder$3.create(ContainerBuilder.java:93)
at com.opensymphony.xwork2.inject.ContainerBuilder$7.call(ContainerBuilder.java:487)
at com.opensymphony.xwork2.inject.ContainerBuilder$7.call(ContainerBuilder.java:484)
at com.opensymphony.xwork2.inject.ContainerImpl.callInContext(ContainerImpl.java:574)
at com.opensymphony.xwork2.inject.ContainerBuilder.create(ContainerBuilder.java:484)
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.createBootstrapContainer(DefaultConfiguration.java:252)
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:193)
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:66)
at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:371)
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:415)
at org.apache.struts2.dispatcher.FilterDispatcher.init(FilterDispatcher.java:190)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275)
at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:397)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:108)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3800)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4450)
at org.apache.catalina.startup.HostConfig.checkResources(HostConfig.java:1173)
at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1271)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:296)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1337)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1601)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1610)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1590)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.reflect.InvocationTargetException
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 com.opensymphony.xwork2.inject.ContainerImpl$MethodInjector.inject(ContainerImpl.java:293)
... 28 more
Caused by: java.lang.ExceptionInInitializerError
at com.opensymphony.xwork2.ognl.OgnlValueStackFactory.setContainer(OgnlValueStackFactory.java:85)
... 33 more
Caused by: java.lang.IllegalArgumentException: Javassist library is missing in classpath! Please add missed dependency!
at ognl.OgnlRuntime.<clinit>(OgnlRuntime.java:165)
... 34 more
Caused by: java.lang.ClassNotFoundException: javassist.ClassPool
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)