@Test
public void testInstant() {
// millisec since epoch
long timestamp = System.currentTimeMillis();
// point in time - now!
Instant instant = Instant.now();
long secEpoch = instant.getEpochSecond();
// missing milli so divide by 1000
Assert.assertEquals(timestamp / 1000, secEpoch);
Assert.assertEquals(instant.getLong(ChronoField.INSTANT_SECONDS), secEpoch);
Instant timestampInstant = Instant.ofEpochMilli(timestamp);
Assert.assertEquals(timestamp, timestampInstant.truncatedTo(ChronoUnit.MILLIS).toEpochMilli());
// different ways to go into the future
Instant future1 = instant.plusMillis(1000);
Instant future2 = instant.plus(1000, ChronoUnit.MILLIS);
// add Duration instead of Period as this example is dealing with time
Instant future3 = instant.plus(Duration.ofMillis(1000));
Instant future4 = instant.plus(Duration.of(1000, ChronoUnit.MILLIS));
// all futures are the same!
Assert.assertEquals(future1, future2);
Assert.assertEquals(future2, future3);
Assert.assertEquals(future3, future4);
}
