public void outputJson(PrintWriter writer) throws LlapStatusCliException {
    ObjectMapper mapper = new ObjectMapper();
    mapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
    mapper.setSerializationInclusion(Include.NON_NULL);
    mapper.setSerializationInclusion(Include.NON_EMPTY);
    mapper.setVisibility(PropertyAccessor.ALL, Visibility.NON_PRIVATE);
    try {
      writer.println(mapper.writerWithDefaultPrettyPrinter().writeValueAsString(appStatusBuilder));
    } catch (IOException e) {
      LOG.warn("Failed to create JSON", e);
      throw new LlapStatusCliException(ExitCode.LLAP_JSON_GENERATION_ERROR, "Failed to create JSON", e);
    }
  }
Checks the status of the Llap.
llap-server/src/java/org/apache/hadoop/hive/llap/cli/status/LlapStatusServiceDriver.java