private void applySystemProperties() {
    Map<String, String> systemProperties = getConfSystemProperties();
    for (Entry<String, String> systemProperty : systemProperties.entrySet()) {
      this.set(systemProperty.getKey(), systemProperty.getValue());
    }
  }
Apply system properties to this object if the property name is defined in ConfVars
and the value is non-null and not an empty string.
common/src/java/org/apache/hadoop/hive/conf/HiveConf.java