项目启动时报错:java.lang.ClassNotFoundException: org.apache.log4j.LogManager 错误信息: java.lang.ClassNotFoundException: org.apache.log4j.LogManager at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1516) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1361) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320) at csnms.start.servlet.StartService.<clinit>(StartService.java:18) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance egatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at java.lang.Class.newInstance0(Class.java:355) at java.lang.Class.newInstance(Class.java:308) at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1116) at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:993) at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4187) at org.apache.catalina.core.StandardContext.start(StandardContext.java:4496) 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:546) at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1041) at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:964) at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:502) at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1277) at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:321) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053) at org.apache.catalina.core.StandardHost.start(StandardHost.java:785) 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:519) at org.apache.catalina.core.StandardServer.start(StandardServer.java:710) at org.apache.catalina.startup.Catalina.start(Catalina.java:581) 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:289) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)