Which is the best way for checking if two Date() object are equals, with null safe feature?
Date d1
Date d2
d1 = null, d2 = new Date() => equal false
d1 = null, d2 = null => equal true
d1 = SAME_INSTANT, d2 = SAME_INSTANT => equal true
d1 = new Date(), d2 = YESTERDAY => equal false
Returns true if the arguments are equal to each other and false otherwise. Consequently, if both arguments are null, true is returned and if exactly one argument is null, false is returned. Otherwise, equality is determined by using the equals method of the first argument.
Since java-7, use:
Objects::equals
And stop using java.util.Date if you can; use Instant when you want Date - easier to work with and a lot less error prone.
Optional.ofNullable(d1).map(d -> d.equals(d2)).orElseGet(() -> d2 == null);
Works when either is null
d1 = new Date(), d2 = new Date()might returnfalsefor a split second around midnight ;)Dateclass, it actually represents a date-time in milliseconds, so the chance of getting two un-equal instances arises once every millisecond. On my machine, the loopdo {} while(new Date().equals(new Date()));completes in a few milliseconds (between five and forty).Dateclass? It’s poorly designed and now long outdated. UseInstantfromjava.time, the modern Java date and time API, instead.