这是我用到的包

比如以下异常，这明显就是没找到包的异常

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

at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:12)

at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1735)

at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:495)

at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:477)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:113)

at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:258)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:105)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4958)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5652)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)

at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:9)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:875)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:679)
at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1966)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)

at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)

at java.lang.Thread.run(Thread.java:745)

怎么回事呢？

原来是仿照老师做的时候，他用的是myeclipse，会自动把library里面的包放到lib下，但是eclipse就需要我们自己去把各种需要的包放进去了。