Date interval sum and subtraction in Java

Question

I'm looking for a library or helper class in Java that would allow me to perform date interval sum and subtractions.

For example, lets's say I have the following date intervals:

A = ["2015-01-01 00:00", "2015-01-20 00:00"]
B = ["2015-01-05 00:00", "2015-01-10 00:00"]
C = ["2015-01-11 00:00", "2015-01-14 00:00"]
D = ["2015-01-19 00:00", "2015-01-25 00:00"]

1                  A               20
|----------------------------------|
    |---------|   |----------|   |------------|
    5    B    10  11    C    14  19    D      25

And let's say I'd like to calculate the following:

A - B - C + D = { ["2015-01-01 00:00", "2015-01-05 00:00"[,
                  ]"2015-01-10 00:00", "2015-01-11 00:00"[,
                  ]"2015-01-14 00:00", "2015-01-25 00:00"] }

1   5         10  11         14               25
|---|         |---|          |----------------|

I know I can build my own logic using pure Java, but I'd rather not reinvent the wheel...

I was looking into Joda-Time, but I couldn't figure out how to perform such operations using it.

Thanks a lot!

Answer 1

I found exactly what I needed: Ranges, from the guava-libraries.

Works like this:

Range<Date> a = Range.closed(
    new GregorianCalendar(2015, 0, 1).getTime(),
    new GregorianCalendar(2015, 0, 20).getTime());
Range<Date> b = Range.closed(
    new GregorianCalendar(2015, 0, 5).getTime(),
    new GregorianCalendar(2015, 0, 10).getTime());
Range<Date> c = Range.closed(
    new GregorianCalendar(2015, 0, 11).getTime(),
    new GregorianCalendar(2015, 0, 14).getTime());
Range<Date> d = Range.closed(
    new GregorianCalendar(2015, 0, 19).getTime(),
    new GregorianCalendar(2015, 0, 25).getTime());

RangeSet<Date> result = TreeRangeSet.create();
result.add(a);
result.remove(b);
result.remove(c);
result.add(d);

System.out.println(result);

The code above prints:

[
    [Thu Jan 01 00:00:00 BRST 2015‥Mon Jan 05 00:00:00 BRST 2015),
    (Sat Jan 10 00:00:00 BRST 2015‥Sun Jan 11 00:00:00 BRST 2015),
    (Wed Jan 14 00:00:00 BRST 2015‥Sun Jan 25 00:00:00 BRST 2015]
]