TOMCAT启动时报下面的错误，请问各位大师，怎么解决啊！
四月 08, 2016 2:52:45 下午 org.apache.catalina.core.StandardContext startInternal
严重: One or more listeners failed to start. Full details will be found in the appropriate container log file
四月 08, 2016 2:52:45 下午 org.apache.catalina.core.StandardContext startInternal
严重: Context [] startup failed due to previous errors
四月 08, 2016 2:52:45 下午 org.apache.catalina.loader.WebappClassLoaderBase clearReferencesJdbc
严重: The web application [] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
四月 08, 2016 2:52:45 下午 org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
严重: The web application [] appears to have started a thread named [Timer-0] but has failed to stop it. This is very likely to create a memory leak.
四月 08, 2016 2:52:45 下午 org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
严重: The web application [] appears to have started a thread named [MySQL Statement Cancellation Timer] but has failed to stop it. This is very likely to create a memory leak.
四月 08, 2016 2:52:45 下午 org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
严重: The web application [] appears to have started a thread named [MultiThreadedHttpConnectionManager cleanup] but has failed to stop it. This is very likely to create a memory leak.