解决org.apache.catalina.LifecycleException: Failed to start component

前言

通过idea运行项目时,无法启动tomcat，google了许久，答案太多。一直到此刻才得以解决。

环境

Server version: Apache Tomcat/9.0.0.M26
Server built:   Aug 2 2017 20:29:05 UTC
Server number:  9.0.0.0
OS Name:        Mac OS X
OS Version:     10.12.5
Architecture:   x86_64
JVM Version:    1.8.0_131-b11
JVM Vendor:     Oracle Corporation

问题

在idea中配置了一个ssm项目,通过idea 运行时，出现如下异常

java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [org.apache.catalina.webresources.StandardRoot@5bfbf16f]
    at java.util.concurrent.FutureTask.report(FutureTask.java:122)
    at java.util.concurrent.FutureTask.get(FutureTask.java:192)
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:947)
    at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:839)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1425)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1415)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
    at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134)
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:941)
    at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:258)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.core.StandardService.startInternal(StandardService.java:422)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:770)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:657)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:355)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:495)

如何解决

打开tomcat安装目录,定位conf/server.xml
注意下面这一行。

   <Context path="" docBase="..." reloadable="true"/> 

注释这一行。

最终

<!-- <Context path="" docBase="..." reloadable="true"/> -->

原因

原因不清楚。

参考

• context参数的解析http://blog.sina.com.cn/s/blog_4b3c1f950100olce.html
• https://stackoverflow.com/questions/28753473/org-apache-catalina-lifecycleexception-failed-to-start-component-standardserve