code: public static void loadFromSystemProperty(String propertyFileSystemProperty, String defaultPropertyFilePath) {
          String path = System.getProperty(propertyFileSystemProperty);
  
          if (path == null) {
              path = defaultPropertyFilePath;
              System.setProperty(propertyFileSystemProperty, path);
              log.info("Using default " + propertyFileSystemProperty + " value: "
                       + path + ".  To override default specify java commandline param -D"
                       + propertyFileSystemProperty + "=/your/prop/file/path/here");
          } else {
              log.info("Using user-defined " + propertyFileSystemProperty + " property: " + path);
          }
  
          if (!new File(path).exists()) {
              log.error(path + " does not exist. It is required to run this application. Exiting...");
              System.exit(1);
          } else {
              try {
                  SystemPropertyLoader.load(path);
              } catch (IOException e) {
                  e.printStackTrace();
              }
          }
      }
docs: Ensures that a specified system property is set with a valid file path.
  If the system property is not set, the specified default value will set instead.
  If the resulting system property value does not resolve to an existing file,
  The system will exit after logging the error.
  
  @param profileFileSystemProperty The system property to check
  @param defaultFilePath           The default property file path