Problema com log4j

PePeLeGaL:

galera,

quando inicializo o tomcat com alguns projetos acontece o seguinte erro:

log4j:WARN No appenders could be found for logger (org.apache.catalina.startup.Bootstrap).

log4j:WARN Please initialize the log4j system properly.

java.lang.reflect.InvocationTargetException

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:294)

at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:432)

Caused by: java.lang.NullPointerException

at org.apache.catalina.startup.Catalina.await(Catalina.java:615)

at org.apache.catalina.startup.Catalina.start(Catalina.java:575)

… 6 more

alguem sabe por que?

Você ta usando o Tomcat certo?? Dá uma olhada no seu log4j.properties

http://www.google.com.br/search?hl=pt-BR&q=log4j.properties+configuracao&btnG=Pesquisa+Google&meta=