tomcatSEVERE: The required Server component failed to start so Tomcat is unable to start

SEVERE: The required Server component failed to start so Tomcat is unable to start. org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]]

切换不同版本的tomcat但是报出这个错误，用其他的版本就是好的。原因是Tomcat的server.xml配置文件最后多出来的这几行，估计是以前在Eclipse上跑的项目自动生成的。把它们删了之后Tomcat就正常运行了。

 

 <Host appBase="webapps" autoDeploy="true" name="localhost" unpackWARs="true">

<Valve className="org.apache.catalina.authenticator.SingleSignOn" />

<Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs" pattern="%h %l %u %t &quot;%r&quot; %s %b" prefix="localhost_access_log." suffix=".txt"/> 

<Context docBase="MyProject" path="/MyProject" reloadable="true" source="org.eclipse.jst.jee.server:MyProject"/></Host>