tomcat无法启动，报如下错误：
严重: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[]]
at java.util.concurrent.FutureTask.report(Unknown Source)
at java.util.concurrent.FutureTask.get(Unknown Source)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1119)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:819)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1571)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1561)
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)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:153)
... 6 more
Caused by: java.lang.NoClassDefFoundError: Lorg/apache/commons/logging/Log;
at java.lang.Class.getDeclaredFields0(Native Method)
at java.lang.Class.privateGetDeclaredFields(Unknown Source)
at java.lang.Class.getDeclaredFields(Unknown Source)
at org.apache.catalina.util.Introspection.getDeclaredFields(Introspection.java:106)
at org.apache.catalina.startup.WebAnnotationSet.loadFieldsAnnotation(WebAnnotationSet.java:270)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationServletAnnotations(WebAnnotationSet.java:139)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:65)
at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:416)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:890)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:387)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5503)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
... 6 more
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.Log
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 20 more
上图说明common-logging的jar包已经加进来了，请问为什么还是报找不到类的错误？
换了个8.0的tomcat就莫名的好了，但是我用同样的tomcat加载其他项目就ok，莫非是tomcat自带的包与项目中的包有冲突？
我没有换过tomc8.0，但我同样换了一个干净的tomcat7.0还是报一样的错，我把Myeclipse本身自带的tomcat也关了，还是报同样的错误，clean一下项目，然后重新build，还是一样的错误，最终在maven的pom.xml文件里加这个依赖，结果就顺利的跑起来啦
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging-api</artifactId>
<version>1.1</version>
</dependency>
最终是顺利的解决了，很奇怪，再其他的电脑上就能正常跑，而换一台就出现这个问题，项目都是检出来的。