SEVERE: The required Server component failed to start so Tomcat is unable to start. org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]]
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 或者注释掉 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 "%r" %s %b" prefix="localhost_access_log." suffix=".txt"/>
<Context docBase="MyProject" path="/MyProject" reloadable="true" source="org.eclipse.jst.jee.server:MyProject"/> -->
</Host>
Tomcat启动报错 Failed to start component [StandardServer[8005]]解决
原文：https://www.cnblogs.com/Samuel-Leung/p/10490249.html