code: private PermConverter getConverter(HttpServletRequest hreq) {
  		if(mapPairs!=null) {
  			String pi = hreq.getPathInfo();
  			if(pi!=null) {
  			for(Pair p: mapPairs) {
  				if(pi.startsWith(p.name))return p.pc;
  			}
  			}
  		}
  		return NullPermConverter.singleton();
  	}
docs: Get Converter by Path