Why was "new Date(int year, int month, int day)" deprecated?

Question

My application I've recently inherited is FULL of deprecation warnings about the constructor:

Date d = new Date(int year, int month, int day)

Does anyone know or can point to a reason why something as simple as this was "replaced" with something like this:

Date d = new Date();
Calendar cal = GregorianCalendar.getInstance();
cal.set(1900 + year, month, day);
d = cal.getTime();

Now, obviously deprecation warnings are not a problem in themselves, but can you imagine the millions of LOC that would be crying out in agony if this constructor was ever removed?

In my brief little play at benchmarking, the latter takes about 50% more time to execute.

Answer 1

The answer is portability.

The class Date is not very flexible. You can define dates, but not with any transformation into other calendar formats. So Sun decided to use an additional class hierarchy (Calendar) to make it more flexibel.

Nonetheless, it's not very handy.

Answer 2

The Java Date APIs have long been critized, see for instance this thread.

You might want to check out Joda-Time or Apache Commons Lang for alternative Date/Time utilities.

Answer 3

Mostly because the original java.util.Date was bloated and not completely timezone aware and not internationalization friendly.

However, Date is still in use and very well, in Value Objects, or say as a data type. As far as you make it immutable explicitly, you can go with ease. I tend to think it must be immutable, for other purpose we have Calendar to manipulate. Where its lot of manipulation expected, one should consider something like, Joda-Time.

[Edited]

Just don't instantiate the Date, in the latter code. Its of no use. You may achieve a better result for your benchmark.

Answer 4

Originally, Date was intended to contain all logic concerning dates, but the API designers eventually realized that the API they had so far was woefully inadequate and could not be cleanly extended to deal correctly with issues such as timezones, locales, different calendars, daylight savings times, etc.

So they created Calendar to deal with all that complexity, and relegated Date to a simple timestamp, deprecating all its functionality that dealt with formatting, parsing and individual date fields.

BTW, internally these methods such as Date(int, int, int) constructor now call Calendar, so if you see a difference in speed, then you're doing something wrong when calling Calendar.

The bottomline: It's not Java's Calendar API that is overly complex, it's the human concept of dates, and the only problem with Calendar is that it offers not much in the way of shortcuts to the most common usages.

Answer 5

Of course, no-one ever uses any other calendar format, but the new API increases the amount of code to write for the 99% common case, so it's a great boon for Java programmers paid by LoC.