title: Relative path in fop xml config
body: <p>I have a PDF export, and I'm using external conf file with link to font-file (font is used for cyrillic glyphs)</p>
  
  <pre><code>&lt;font metrics-url="file:////fonts/DejaVuSerif.xml" kerning="yes" embed-url="file:////fonts/DejaVuSerif.ttf"&gt;
  &lt;font-triplet name="DejaVu Serif" style="normal" weight="normal"/&gt;&lt;/font&gt;
  </code></pre>
  
  <p>but in this case, it causes <code>java.io.FileNotFoundException: /fonts/DejaVuSerif.xml</code></p>
  
  <p>problem is how to locate the correct path
  I know a local path /usr/lib/tomcat/webapps/myProject/WEB-INF/fonts/DeJavuSerif.xml
  but how to locale <strong>relative</strong> path, for example </p>
  
  <pre><code>&lt;font metrics-url="file:///**${contextPath}**/fonts/DejaVuSerif.xml" kerning="yes" 
  embed-url="file:///**${contextPath}**/fonts/DejaVuSerif.ttf"&gt;
  &lt;font-triplet name="DejaVu Serif" style="normal" weight="normal"/&gt;&lt;/font&gt;
  </code></pre>