Debug:tomcat:Web app root system property already set to different value:

异常原因：tomcat启动了两个相似的项目。

解决方法1：删除一个，只部署一个

解决方法2：web.xml中加入--------------------------

<context-param>

<param-name>webAppRootKey</param-name>

<param-value>项目名称</param-value>

</context-param>

java.lang.IllegalStateException: Web app root system property already set to different value: 'webapp.root' = [E:\DevelopProject\pdata\WebRoot\] instead of [D:\DevelopWare\apache-tomcat-7.0.33\webapps\pdata\] - 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:4791)

at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5285)

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:633)

at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1114)

at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1673)

at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)

at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)

at java.util.concurrent.FutureTask.run(FutureTask.java:138)

at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)

at java.lang.Thread.run(Thread.java:619)