title: About log4j.xml NullAppender
body: <p>I have done some Googling around it but couldn't find any relevant information. <code>log4j</code> supports a bunch of log <code>appenders</code>, there's documentation all over the net about <code>ConsoleAppender</code> and <code>FileAppender</code>, but there are very little or no information about appenders such as <code>NullAppender</code>, <code>JDBCAppender</code> etc. I am particularly interested about <code>NullAppender</code>. </p>
  
  <pre><code>&lt;appender name="???" class="org.apache.log4j.varia.NullAppender"&gt;
  &lt;appender name="???" class="org.apache.log4j.jdbc.JDBCAppender"&gt;
  </code></pre>
  
  <p>Does anyone have any specific info on these? especially on the <code>NullAppender</code>?</p>
  
  <p>I started looking <a href="http://wiki.apache.org/logging-log4j/Log4jXmlFormat" rel="nofollow">here</a>.</p>