启动项目报错this web application instance has been stopped already.

1.tomcat底下catalina.out日志报如下错误

25-Jul-2016 18:06:41.568 INFO [commons-pool-EvictionTimer] org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading Illegal access: this web application instance has been stopped already. Could not load [redis.clients.jedis.exceptions.JedisDataException]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
 java.lang.IllegalStateException: Illegal access: this web application instance has been stopped already. Could not load [redis.clients.jedis.exceptions.JedisDataException]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
	at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading(WebappClassLoaderBase.java:1319)
	at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForClassLoading(WebappClassLoaderBase.java:1307)
	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1172)
	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1133)
	at redis.clients.jedis.JedisFactory.makeObject(JedisFactory.java:83)
	at org.apache.commons.pool2.impl.GenericObjectPool.create(GenericObjectPool.java:861)
	at org.apache.commons.pool2.impl.GenericObjectPool.ensureIdle(GenericObjectPool.java:920)
	at org.apache.commons.pool2.impl.GenericObjectPool.ensureMinIdle(GenericObjectPool.java:899)
	at org.apache.commons.pool2.impl.BaseGenericObjectPool$Evictor.run(BaseGenericObjectPool.java:1036)
	at java.util.TimerThread.mainLoop(Timer.java:555)
	at java.util.TimerThread.run(Timer.java:505)

Exception in thread "commons-pool-EvictionTimer" java.lang.NoClassDefFoundError: redis/clients/jedis/exceptions/JedisDataException
	at redis.clients.jedis.JedisFactory.makeObject(JedisFactory.java:83)
	at org.apache.commons.pool2.impl.GenericObjectPool.create(GenericObjectPool.java:861)
	at org.apache.commons.pool2.impl.GenericObjectPool.ensureIdle(GenericObjectPool.java:920)
	at org.apache.commons.pool2.impl.GenericObjectPool.ensureMinIdle(GenericObjectPool.java:899)
	at org.apache.commons.pool2.impl.BaseGenericObjectPool$Evictor.run(BaseGenericObjectPool.java:1036)
	at java.util.TimerThread.mainLoop(Timer.java:555)
	at java.util.TimerThread.run(Timer.java:505)
Caused by: java.lang.ClassNotFoundException: Illegal access: this web application instance has been stopped already. Could not load [redis.clients.jedis.exceptions.JedisDataException]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
	at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForClassLoading(WebappClassLoaderBase.java:1309)
	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1172)
	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1133)
	... 7 more
Caused by: java.lang.IllegalStateException: Illegal access: this web application instance has been stopped already. Could not load [redis.clients.jedis.exceptions.JedisDataException]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
	at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading(WebappClassLoaderBase.java:1319)
	at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForClassLoading(WebappClassLoaderBase.java:1307)
	... 9 more

2.查看localhost.xxxx-xx-xx.log日志可以看到，需要在web.xml中配置webAppRootKey参数

25-Jul-2016 18:06:12.112 SEVERE [localhost-startStop-1] org.apache.catalina.core.StandardContext.listenerStart 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' = [/root/tomcat/webapps/product-statis/] instead of [/root/tomcat/webapps/product-quartz/] - Choose unique values for the 'webAppRootKey' context-param in your web.xml files!
	at org.springframework.web.util.WebUtils.setWebAppRootSystemProperty(WebUtils.java:146)
	at org.springframework.web.util.Log4jWebConfigurer.initLogging(Log4jWebConfigurer.java:118)
	at org.springframework.web.util.Log4jConfigListener.contextInitialized(Log4jConfigListener.java:47)
	at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4732)
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5194)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:152)
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:724)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:700)
	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
	at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:952)
	at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1823)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)

3.两个工程需要在web.xml中配置如下参数，不能相同

  webAppRootKey
  xxxx