Clean Code - Functions snippet four

CleanCodeFunctionsFour.java

public int compareTo(final Object _other) throws ClassCastException, NullPointerException {
  final ExampleClass otherExampleClass= (ExampleClass) _other;
  return compareThisTo( otherExampleClass);
}

private int compareThisTo(final ExampleClass _otherExampleClass) {
  if(equals(_otherExampleClass)) {
    return 0;
  }
  return compareCreatedDates(_otherExampleClass);
}

private int compareCreatedDates(final ExampleClass _otherExampleClass) {
  if(isThisAndOthersCreatedDateNull(_otherExampleClass)) {
    return 0;
  }
  if (isThisCreatedDateNull()) {
    return 1;
  }
  if (isOthersCreatedDateNull(_otherExampleClass)) {
    return 1;
  }
  return compareCreatedDatesThatAreNotNull(_otherExampleClass);
}

private boolean isThisAndOthersCreatedDateNull(final ExampleClass _otherExampleClass) {
  return isThisCreatedDateNull() && isOthersCreatedDateNull(_otherExampleClass);
}

private  boolean isThisCreatedDateNull() {
  return isOthersCreatedDateNull(this);
}

private boolean isOthersCreatedDateNull(ExampleClass _otherExampleClass) {
  return _otherExampleClass.getCreatedDate() == null;
}

private int compareCreatedDatesThatAreNotNull(ExampleClass _otherExampleClass) {
  return _otherExampleClass.getCreatedDate().compareTo(getCreatedDate());
}