Duration.MAX_VALUE

[Pavel Rappo]

Couldn't recall or quickly find if this was asked before.

I come across this quite often: there doesn’t seem to be a readily
available maximum value for java.time.Duration -- a value that
represents the longest possible duration.

I assume there are plenty of homegrown constants out in the wild
addressing this. Don’t get me wrong: it’s not hard to create one. The
issue, in my experience, is that it takes time and sometimes
experimentation.

Unless one reads the Javadoc carefully, it’s not obvious that the
maximum duration can be constructed as follows:

    Duration.of(Long.MAX_VALUE, 999_999_999);

Naturally, one might first try using IDE autocomplete. For example,
creating a Duration from Long.MAX_VALUE of a large unit -- millennia,
centuries, decades, etc. -- only to run into ArithmeticException. Only
when reaching seconds does it finally work:

    Duration.ofSeconds(Long.MAX_VALUE);

or

    Duration.of(Long.MAX_VALUE, ChronoUnit.SECONDS);

Of course, there’s no practical difference between
Duration.of(Long.MAX_VALUE, 999_999_999) and
Duration.ofSeconds(Long.MAX_VALUE). We’re talking about durations on
the order of 292 billion years, after all. The exact value isn’t the
problem. The problem is that the values are inconsistent, and arriving
to them is error-prone. Adding a constant to java.time.Duration would
simplify things.

-Pavel