错误信息：
1 SEVERE: Exception starting filter struts2 2 java.lang.NoClassDefFoundError: org/objectweb/asm/ClassVisitor 3 at org.apache.struts2.convention.PackageBasedActionConfigBuilder.findActions(PackageBasedActionConfigBuilder.java:390) 4 at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildActionConfigs(PackageBasedActionConfigBuilder.java:347) 5 at org.apache.struts2.convention.ClasspathPackageProvider.loadPackages(ClasspathPackageProvider.java:53) 6 at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:260) 7 at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:67) 8 at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:429) 9 at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:473) 10 at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74) 11 at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:51) 12 at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:281) 13 at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:262) 14 at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:107) 15 at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4775) 16 at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5452) 17 at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) 18 at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559) 19 at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549) 20 at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source) 21 at java.util.concurrent.FutureTask.run(Unknown Source) 22 at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) 23 at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) 24 at java.lang.Thread.run(Unknown Source) 25 Caused by: java.lang.ClassNotFoundException: org.objectweb.asm.ClassVisitor 26 at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714) 27 at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559) 28 ... 22 more
经百度后得知，需要添加一下jar包。
- asm-commons-3.3.jar
- asm-3.3.jar
- asm-tree-3.3.jar