java.lang.NoClassDefFoundError: com/opensymphony/x

问题：
严重: Unable to read class [com.spml.action.AddUserAction]
java.lang.NoClassDefFoundError: com/opensymphony/xwork2/util/finder/DefaultClassFinder$InfoBuildingVisitor
    at com.opensymphony.xwork2.util.finder.DefaultClassFinder.readClassDef(DefaultClassFinder.java:473)
    at com.opensymphony.xwork2.util.finder.DefaultClassFinder.<init>(DefaultClassFinder.java:96)
    at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildClassFinder(PackageBasedActionConfigBuilder.java:416)
    at org.apache.struts2.convention.PackageBasedActionConfigBuilder.findActions(PackageBasedActionConfigBuilder.java:397)
    at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildActionConfigs(PackageBasedActionConfigBuilder.java:354)
    at org.apache.struts2.convention.ClasspathPackageProvider.loadPackages(ClasspathPackageProvider.java:53)
    at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:274)
    at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:67)
    at org.apache.struts2.dispatcher.Dispatcher.getContainer(Dispatcher.java:967)
    at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:435)
    at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:479)
    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:4854)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5542)
    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:649)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1245)
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1895)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

解决问题：

要在项目中加入asm-commons-3.3.jar包