tomcat下啟動(dòng)多個(gè)應(yīng)用時(shí)可能遇到的異常：

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INFO: Starting ProtocolHandler ["ajp-bio-9009"]
Oct 25, 2016 10:00:26 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 14612 ms
Oct 25, 2016 10:00:27 PM org.apache.catalina.loader.WebappClassLoaderBase loadClass
INFO: Illegal access: this web application instance has been stopped already.  Could not load org.springframework.core.NestedExceptionUtils.  The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
java.lang.IllegalStateException
 at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1745)
 at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1703)
 at org.springframework.core.NestedRuntimeException.<clinit>(NestedRuntimeException.java:45)
 at org.springframework.scheduling.quartz.SchedulerFactoryBean$1.run(SchedulerFactoryBean.java:672)

Exception in thread "Quartz Scheduler [scheduler]" java.lang.NoClassDefFoundError: org/springframework/core/NestedExceptionUtils
 at org.springframework.core.NestedRuntimeException.<clinit>(NestedRuntimeException.java:45)
 at org.springframework.scheduling.quartz.SchedulerFactoryBean$1.run(SchedulerFactoryBean.java:672)
Caused by: java.lang.ClassNotFoundException: org.springframework.core.NestedExceptionUtils
 at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1854)
 at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1703)
 ... 2 more

原因

看日志以為是“com.xxx.xxx.xxxxxxx”類(lèi)加載異常，其實(shí)這個(gè)只是現(xiàn)象，不不是真正引起問(wèn)題的原因。
看這個(gè)真正的異常原因需要看tomcat/logs/localhost.年-月-日.log的文件，這個(gè)文件中會(huì)描述正真的錯(cuò)誤原因。

tomcat/logs/localhost.年-月-日.log`的文件

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Oct 25, 2016 5:00:54 PM org.apache.catalina.core.StandardContext listenerStart
SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.util.Log4jConfigListener
java.lang.IllegalStateException: Web app root system property already set to different value: 'webapp.root' = [/home/vhsworkdic/zicai/webapps/cbsService/] instead of [/home/vhsworkdic/zicai/webapps/zicai/] - Choose unique values for the 'webAppRootKey' context-param in your web.xml files!
 at org.springframework.web.util.WebUtils.setWebAppRootSystemProperty(WebUtils.java:151)
 at org.springframework.web.util.Log4jWebConfigurer.initLogging(Log4jWebConfigurer.java:116)
 at org.springframework.web.util.Log4jConfigListener.contextInitialized(Log4jConfigListener.java:45)
 at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:5003)
 at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5517)
 at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
 at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
 at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
 at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
 at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1095)
 at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1960)
 at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
 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)

從日志文件可以看出是說(shuō)Web應(yīng)用程序根系統(tǒng)屬性已經(jīng)被設(shè)置，'webapp.root' 這個(gè)配置名稱(chēng)已經(jīng)被使用，提示了Choose unique values for the 'webAppRootKey' context-param in your web.xml files ，也就是說(shuō)在web.xml里配置一個(gè)唯一的'webAppRootKey' ，這樣就不會(huì)發(fā)生沖突。

解決辦法

在web.xml指定webAppRootKey

<context-param>  
    <param-name>webAppRootKey</param-name>  
    <param-value>myapp.root</param-value>  
</context-param>