我用strut2时遇到的问题请各位大神帮忙看一下

严重: Exception starting filter struts2
java.lang.reflect.InvocationTargetException - Class: com.opensymphony.xwork2.inject.ContainerImpl$MethodInjector
File: ContainerImpl.java
Method: inject
Line: 295 - com/opensymphony/xwork2/inject/ContainerImpl.java:295:-1
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:428)
at org.apache.struts2.dispatcher.FilterDispatcher.init(FilterDispatcher.java:190)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:295)
at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:422)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:115)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4071)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4725)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:799)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:779)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:601)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1079)
at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:1002)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:506)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1315)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:324)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:142)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1061)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:840)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463)
at org.apache.catalina.core.StandardService.start(StandardService.java:525)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:754)
at org.apache.catalina.startup.Catalina.start(Catalina.java:595)
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:289)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
Caused by: 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$7.call(ContainerBuilder.java:484)
at com.opensymphony.xwork2.inject.ContainerImpl.callInContext(ContainerImpl.java:574)
at com.opensymphony.xwork2.inject.ContainerBuilder.create(ContainerBuilder.java:484)
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.createBootstrapContainer(DefaultConfiguration.java:252)
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:193)
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:66)
at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:371)
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:415)
... 28 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.opensymphony.xwork2.inject.ContainerImpl$MethodInjector.inject(ContainerImpl.java:293)
... 41 more
Caused by: java.lang.ExceptionInInitializerError
at com.opensymphony.xwork2.ognl.OgnlValueStackFactory.setContainer(OgnlValueStackFactory.java:85)
... 46 more
Caused by: java.lang.IllegalArgumentException: Javassist library is missing in classpath! Please add missed dependency!
at ognl.OgnlRuntime.<clinit>(OgnlRuntime.java:165)
... 47 more
Caused by: java.lang.ClassNotFoundException: javassist.ClassPool
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at ognl.OgnlRuntime.<clinit>(OgnlRuntime.java:162)
... 47 more