Tomcat 7 - java.lang.NoClassDefFoundError： org/apache/log4j/spi/ThrowableInformation

我面临以下异常：

Mar 26, 2012 1:20:34 PM org.apache.catalina.loader.WebappClassLoader loadClass
INFO: Illegal access: this web application instance has been stopped already.  
Could not   load org.apache.log4j.spi.ThrowableInformation.  
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.WebappClassLoader.loadClass(WebappClassLoader.java:1562)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
at org.apache.log4j.spi.LoggingEvent.<init>(LoggingEvent.java:165)
at org.apache.log4j.Category.forcedLog(Category.java:391)
at org.apache.log4j.Category.error(Category.java:322)
at com.abc.supervisionmanager.Monitoring.run(Monitoring.java:205)
at java.lang.Thread.run(Thread.java:662)
Exception in thread "Thread_Monitoring" java.lang.NoClassDefFoundError: org/apache/log4j/spi/ThrowableInformation
at org.apache.log4j.spi.LoggingEvent.<init>(LoggingEvent.java:165)
at org.apache.log4j.Category.forcedLog(Category.java:391)
at org.apache.log4j.Category.error(Category.java:322)
at com.abc.supervisionmanager.Monitoring.run(Monitoring.java:205)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.ClassNotFoundException: org.apache.log4j.spi.ThrowableInformation
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1676)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
... 5 more

我用谷歌搜索了这个异常，发现大多数答案都指出它是tomcat 5.5中的错误，它将在5.5.28版本中得到解决。

但是，我目前正在使用带有log4j-1.2.16的tomcat 7.11.jar我仍然面临同样的问题。