【Tomcat】热部署的遗留配置导致服务器无法启动

1、问题描述：
今天用myeclipse写了个小demo，然后用Tomcat7 部署了，接着点击启动服务器，服务器居然报错：
严重: Error starting static Resources
java.lang.IllegalArgumentException: Document base H:softwareapache-tomcatapache-tomcat-7.0.52webappslemon does not exist or is not a readable directory
       at org.apache.naming.resources.FileDirContext.setDocBase(FileDirContext.java:136)
       at org.apache.catalina.core.StandardContext.resourcesStart(StandardContext.java:5089)
       at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5269)
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
       at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
       at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
       at java.util.concurrent.FutureTask.run(FutureTask.java:262)
       at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
       at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
       at java.lang.Thread.run(Thread.java:745)
四月 22, 2017 6:57:41 下午 org.apache.catalina.core.ContainerBase startInternal
严重: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/lemon]]
       at java.util.concurrent.FutureTask.report(FutureTask.java:122)
       at java.util.concurrent.FutureTask.get(FutureTask.java:188)
       at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123)
       at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:799)
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
       at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
       at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
       at java.util.concurrent.FutureTask.run(FutureTask.java:262)
       at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
       at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
       at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/lemon]]
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
       ... 6 more
Caused by: org.apache.catalina.LifecycleException: Error in resourceStart()
       at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5270)
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
       ... 6 more
四月 22, 2017 6:57:41 下午 org.apache.catalina.core.ContainerBase startInternal
严重: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
       at java.util.concurrent.FutureTask.report(FutureTask.java:122)
       at java.util.concurrent.FutureTask.get(FutureTask.java:188)
       at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123)
       at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:300)
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
       at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
       at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:731)
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
       at org.apache.catalina.startup.Catalina.start(Catalina.java:689)
       at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
       at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
       at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
       at java.lang.reflect.Method.invoke(Method.java:606)
       at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:321)
       at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:455)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
       at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
       at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
       at java.util.concurrent.FutureTask.run(FutureTask.java:262)
       at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
       at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
       at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
       at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131)
       at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:799)
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
       ... 6 more
四月 22, 2017 6:57:41 下午 org.apache.catalina.startup.Catalina start
严重: The required Server component failed to start so Tomcat is unable to start.
org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]]
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
       at org.apache.catalina.startup.Catalina.start(Catalina.java:689)
       at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
       at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
       at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
       at java.lang.reflect.Method.invoke(Method.java:606)
       at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:321)
       at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:455)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Catalina]]
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
       at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:731)
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
       ... 7 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina]]
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
       at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
       ... 9 more
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
       at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131)
       at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:300)
       at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
       ... 11 more
2、问题分析：
Document base H:softwareapache-tomcatapache-tomcat-7.0.52webappslemon does not exist or is not a
这句话告诉我们在tomcat的webapps下找不到lemon这个项目 看了看 确实没有. 
此时，我能想到的就是work这个临时文件夹，一般出错都是这个临时文件夹搞的鬼，但是delete掉后，问题依旧。
思来想去，想起了eclipse的workspace下的.metadata下的plugins内的插件org.eclipse.wst.server.core下有个配置文件servers.xml是指定部署项目的相关配置.
于是，我就想myeclipse一般是部署在真实的tomcat上，应该会修改 tomcat的配置文件，因此我找到了tomcat的配置文件server.xml
打开发现，
3、问题解决：
查了下context标签的意思，原来，
<!-- tomcat配置的虚拟路径 docBase="应用的实际目录" 如果用myclipse编写 则是webRoot Tomcat热部署 -->
      <!-- <Context docBase="lemon" path="/lemon" reloadable="true" source="org.eclipse.jst.j2ee.server:lemon"/> -->
最后，我分析可能是因为我们在用myeclipse开发时，由于某种误操作导致myeclipse没有及时去更新server.xml配置文件，导致遗留了一些无效配置。
删掉最后的那句<!-- <Context docBase="lemon" path="/lemon" reloadable="true" source="org.eclipse.jst.j2ee.server:lemon"/> -->，服务器正常启动!
 
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原文地址：https://www.cnblogs.com/dantefung/p/6748836.html