log4j WARN No appenders

log4j:WARN No appenders could be found

원인: CLASSPATH에서 log4j.properties/log4j.xml 미발견

해결: WEB-INF/classes/log4j.properties 생성

log4j.rootLogger=DEBUG, A1
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout

또는 web.xml:

<context-param>
  <param-name>log4jConfigLocation</param-name>
  <param-value>/WEB-INF/log4j.properties</param-value>
</context-param>