如何检查joda时间是否现在正在发生？

Question

I have a list of Instants, I want to iterate though all of them and figure out if any of them are occurring right now. Is that possible to do with Instants or did I confuse myself?

Was I was supposed to use two dateTime's one for beginning of event and one for after and check that way?

Answer 1

Assuming you mean the class org.joda.time.DateTime when speaking about "Instant" you have to notice that the answer depends on granularity needed for your purpose. Normally an instant in JodaTime is fine granular down to milliseconds. If you want to compare any instant with "now", meaning DateTime.now() , then I recommend to use an interval instead like following:

DateTime now = DateTime.now();
DateTime from = now.minusMinutes(1); // example - maybe you need seconds instead
DateTime to = now.plusMinutes(1); // example - maybe you need seconds instead
Interval range = new Interval(from, to);

for (DateTime test : instants) { // supposing instants as List<DateTime>
  if (range.contains(test)) {
    return test;
  }
}

// here not found any equality, process according to your needs

Bare in mind that if you use equals() instead then you will hardly hit any instant you might have in your list. And furthermore, the method equals(Object) compares absolute time AND chronology (including time zones). The alternative isEqual(ReadableInstant) only compares the absolute times which is probably better, but due to granularity issues also not ideal.