【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:\software\apache-tomcat\apache-tomcat-7.0.52\webapps\lemon 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:\software\apache-tomcat\apache-tomcat-7.0.52\webapps\lemon 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!