public static String loadTextFileWithEncoding(String fileName, S encoding) {
  return loadTextFileWithEncoding(fileName, null, encoding);
}

public static String loadTextFileWithEncoding(String fileName, String defaultContents, S encoding) {
  try {
    if (!new File(fileName).exists())
      return defaultContents;

    FileInputStream fileInputStream = new FileInputStream(fileName);
    InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream, encoding);
    return loadTextFile(inputStreamReader);
  } catch (IOException e) {
    throw new RuntimeException(e);
  }
}

  public static String loadTextFileWithEncoding(File f, String defaultContents, S encoding) {
    ret f == null ? defaultContents : loadTextFileWithEncoding(f.getPath(), defaultContents, encoding);
  }
  
public static String loadTextFileWithEncoding(File fileName, S encoding) {
  return loadTextFileWithEncoding(fileName, null, encoding);
}

Began life as a copy of #1001049