请大神帮我看看，我实在不知道怎么搞

严重: Exception starting filter struts2

java.lang.ClassNotFoundException: org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter

at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1358)

at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1204)

at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:249)

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:3693)

at org.apache.catalina.core.StandardContext.start(StandardContext.java:4340)

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:525)

at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:920)

at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:883)

at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:492)

at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1138)

at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:311)

at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)

at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)

at org.apache.catalina.core.StandardHost.start(StandardHost.java:719)

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:566)

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)

2017-6-4 22:11:09 org.apache.catalina.core.StandardContext start

严重: Error filterStart

2017-6-4 22:11:09 org.apache.catalina.core.StandardContext start

严重: Context [/DormManage] startup failed due to previous errors