code: public  void configureClassPath()
      throws Exception
      {
          //cannot configure if the context is already started
          if (_context.isStarted())
          {
              if (log.isDebugEnabled()){log.debug("Cannot configure webapp after it is started");};
              return;
          }
          
          Resource webInf=_context.getWebInf();
          
          // Add WEB-INF classes and lib classpaths
          if (webInf != null && webInf.isDirectory())
          {
              // Look for classes directory
              Resource classes= webInf.addPath("classes/");
              if (classes.exists())
                  _context.setClassPath(classes.toString());
              else
                  _context.setClassPath(null);
    
              // Look for jars
              Resource lib= webInf.addPath("lib/");
              _context.addClassPaths(lib);
          }
       }
docs: Configure ClassPath.
  This method is called before the context ClassLoader is created.
  Paths and libraries should be added to the context using the setClassPath,
  addClassPath and addClassPaths methods.  The default implementation looks
  for WEB-INF/classes, WEB-INF/lib/*.zip and WEB-INF/lib/*.jar
  @throws Exception