title: LOG4J - Avoid same message two times in log
body: <p>Here is my <code>log4j.properties</code> file</p>
  
  <pre class="lang-none prettyprint-override"><code># Set loggers' levels
  log4j.rootLogger=warn, trace_file
  
  # Appender
  log4j.appender.trace_file=org.apache.log4j.RollingFileAppender
  log4j.appender.trace_file.Append=true
  log4j.appender.trace_file.File=log/myLog.log
  log4j.appender.trace_file.MaxFileSize=10MB
  log4j.appender.trace_file.MaxBackupIndex=50
  
  # PatternLayout
  log4j.appender.trace_file.layout=org.apache.log4j.PatternLayout
  log4j.appender.trace_file.layout.ConversionPattern=%d [%p] (%F:%L) %m%n
  
  # Classes
  log4j.logger.my_package=info, trace_file
  </code></pre>
  
  <p>What I want :</p>
  
  <ul>
  <li>Store log requests from <code>my.package</code> in <code>trace_file</code> with at least <code>INFO</code> level</li>
  <li>Store log requests from all other loggers in <code>trace_file</code> ONLY if it's at least <code>WARN</code> level </li>
  </ul>
  
  <p>My configuration does'nt work. If <code>my.package</code> raises a log request of level <code>WARN</code>, this log request gets written two times. If I use two separate appenders, there is no problem.</p>
  
  <p>What am I missing ?</p>