help write log4j output to a file

[Bob Peterson]

I'm trying to get log4j up and running quickly for the first time. I just want to write everything to a file. What would the log4j.properties file look like for that? I've tried:

log4j.rootCategory=default
log4j.appender.default=org.apache.log4j.RollingFileAppender
log4j.appender.File=example.log

But I get log4j warnings :

log4j:WARN No appenders could be found for logger (Log4J).
log4j:WARN Please initialize the log4j system properly.

[Barry Gaunt]

You have probably fixed this yourself by now, but this is what I did to get your example to work:

log4j.rootLogger=ALL,default
log4j.appender.default=org.apache.log4j.RollingFileAppender
log4j.appender.default.File=example.log
log4j.appender.default.layout=org.apache.log4j.SimpleLayout
  

Notice the level ALL on the rootLogger (rootCategory is obsolete) and the addition of the layout line.