use username and pwd to login issue

[Mrwb]

I use log4mongo to record log in mongo,when mongo has not password ,it works correctly,but when i config this words:
log4j.appender.MongoDB.userName=Kneebrace#wr@mongo
log4j.appender.MongoDB.password=kb#wr@mongo
Tomcat doesn't start up,log like this:
No such logging.properties in classpath for jdk logging config!
NoClassDefFoundError: Could not initialize class org.apache.log4j.LogManager

I don't what happened,please tell me whatever about this issue.Thanks.

[Mrwb]

I found out another issue,when i set log level is info,this can't find mongodb instance.I start up a mongodb instance.