我用的是MyEclipse 2014 企业版，tomcat 7.0.54，struts2：2.3.16
web.xml文件：
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
id="WebApp_ID" version="3.0">
<display-name>Test2</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
在建立一个web应用，部署后，tomcat启动报以下错误：
com.opensymphony.xwork2.util.logging.commons.CommonsLogger error
严重: Dispatcher initialization failed
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at com.opensymphony.xwork2.inject.ContainerImpl$MethodInjector.inject(ContainerImpl.java:301)
at com.opensymphony.xwork2.inject.ContainerImpl$ConstructorInjector.construct(ContainerImpl.java:438)
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$7.call(ContainerBuilder.java:484)
at com.opensymphony.xwork2.inject.ContainerImpl.callInContext(ContainerImpl.java:584)
at com.opensymphony.xwork2.inject.ContainerBuilder.create(ContainerBuilder.java:484)
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.createBootstrapContainer(DefaultConfiguration.java:340)
at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:229)
at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:67)
at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:445)
at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:489)
at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:57)
at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:279)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:260)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:105)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4809)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5485)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:632)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1247)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1898)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.reflect.InvocationTargetException
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 com.opensymphony.xwork2.inject.ContainerImpl$MethodInjector.inject(ContainerImpl.java:299)
... 31 more
Caused by: java.lang.ExceptionInInitializerError
at com.opensymphony.xwork2.ognl.OgnlValueStackFactory.setContainer(OgnlValueStackFactory.java:84)
... 36 more
Caused by: java.lang.IllegalArgumentException: Javassist library is missing in classpath! Please add missed dependency!
at ognl.OgnlRuntime.<clinit>(OgnlRuntime.java:168)
... 37 more
Caused by: java.lang.ClassNotFoundException: javassist.ClassPool
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1720)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:190)
at ognl.OgnlRuntime.<clinit>(OgnlRuntime.java:165)
... 37 more
org.apache.catalina.core.StandardContext filterStart
严重: Exception starting filter struts2