title: Load log4j2.xml file outside project with enviroment variable
body: <p>I am developing a java web-app (v3.0) for a TomCat 7.0 server and I am having troubles loading the <code>log4j2.xm</code>l file.</p>
  
  <p>I have defined the <code>log4j2.xml</code> file outside my project and defined the path for the file in my web.xml file.</p>
  
  <p>If i hardcode the path my <code>log4j2.xml</code> file loads as it should.</p>
  
  <pre><code>&lt;context-param&gt;
      &lt;param-name&gt;log4jConfiguration&lt;/param-name&gt;
      &lt;param-value&gt;file:///C:/my/path/log4j2.xml&lt;/param-value&gt;
  &lt;/context-param&gt;    
  </code></pre>
  
  <p>On the other hand I want to use an enviroment variable to define the path.</p>
  
  <pre><code>&lt;context-param&gt;
      &lt;param-name&gt;log4jConfiguration&lt;/param-name&gt;
      &lt;param-value&gt;file:///${ENVIROMENT_VARIABLE}/log4j2.xml&lt;/param-value&gt;
  &lt;/context-param&gt;
  </code></pre>
  
  <p>When I start TomCat I have this error:  </p>
  
  <pre><code>ERROR SatusLogger Unable to access file:///$%7BENVIROMENT_VARIABLE%7D/log4j2.xml
  </code></pre>
  
  <p>It looks like it isn't 'translating' the variable.</p>
  
  <p>Any help will be very aprecciated.</p>
  
  <p>PD: Sorry for my english.</p>