code: public static ContentSource getInputContentSource(Configuration conf) 
      throws URISyntaxException, XccConfigException, IOException {
          String host = conf.getStrings(INPUT_HOST)[0];
          if (host == null || host.isEmpty()) {
              throw new IllegalArgumentException(INPUT_HOST + 
                      " is not specified.");
          }
          
          return getInputContentSource(conf, host);
      }
docs: Get content source for input server.
  @param conf job configuration.
  @return ContentSource for input server.
  @throws URISyntaxException
  @throws XccConfigException
  @throws IOException