code: public static void loadPropertiesFromResources(String path) 
              throws IOException {
          if (instance == null) {
              instance = getConfigInstance();
          }
          ClassLoader loader = Thread.currentThread().getContextClassLoader();
          Enumeration<URL> resources = loader.getResources(path);
          if (!resources.hasMoreElements()) {
              //non-existent config path. Throw an exception. Issue #150
              throw new IOException("Cannot locate " + path + " as a classpath resource.");
          }
          while (resources.hasMoreElements()) {
              URL url = resources.nextElement();
              InputStream fin = url.openStream();
              Properties props = ConfigurationUtils.loadPropertiesFromInputStream(fin);
              if (instance instanceof AggregatedConfiguration) {
                  String name = getConfigName(url);
                  ConcurrentMapConfiguration config = new ConcurrentMapConfiguration();
                  config.loadProperties(props);
                  ((AggregatedConfiguration) instance).addConfiguration(config, name);
              } else {
                  ConfigurationUtils.loadProperties(props, instance);
              }
          }
      }
docs: Load properties from resource file(s) into the system wide configuration
  @param path relative path of the resources
  @throws IOException