private void buildServiceJson(Multimap<AbstractUpgradeCatalog.ConfigUpdateType, Entry<String, String>> propertiesToLog,
                                String configType, String serviceName, JsonObject rootJson) {
    JsonElement serviceJson = null;
    serviceJson = rootJson.get(serviceName);
    JsonObject serviceJsonObject = null;
    if (serviceJson != null) {
      serviceJsonObject = serviceJson.getAsJsonObject();
    } else {
      serviceJsonObject = new JsonObject();
    }
    buildConfigJson(propertiesToLog, serviceJsonObject, configType);
    if (serviceName == null) {
      serviceName = "General";
    }

    rootJson.add(serviceName, serviceJsonObject);
  }
Find, read, and parse the log4j.properties file.
@return the properties that were found or empty if no file was found
ambari-server/src/main/java/org/apache/ambari/server/configuration/Configuration.java