I'd like to make a method called "isBetween" returning a boolean, seeing if a GregorianCalendar date falls between two others. Alternatively, I'd like to just define operators of < and > for the class. I'm pretty new to Java, so I'm not sure....can I even do either of those? If so, how?
+1
A:
No, you can't add method to pre-existing classes and you can't do operator overloading either in Java.
As an alternative, you could provide a static utility method in your own class for example.
Joachim Sauer
2010-03-09 14:22:58
A:
You should try to extend it:
class MyGregorianCalendar extends GregorianCalendar
Aito
2010-03-09 14:24:09
+6
A:
Java does not support monkeypatching or operator overloading, but feel free to subclass GregorianCalendar and add whatever methods you need.
But then, do you really need a new method to do cal.after(startCal) && cal.before(endCal) ?
Michael Borgwardt
2010-03-09 14:25:55
Clearly, I missed the existence of before and after. I saw them about a minute before seeing your answer. Thanks
timdiggerm
2010-03-09 14:32:14
@timdiggerm: the Calendar API is big and disorganized, so it's easy to overlook things, especially methods in the abstract superclass...
Michael Borgwardt
2010-03-09 14:38:19
+1
A:
I would advise against extending the class - you're not adding any behaviour which is specific to instances of a particular class, you're expressing logic which is applicable for any GregorianCalendar (or possibly any calendar at all).
As Joachim says, a static method in a utility class is the way to go - and if Java ever gains extension methods as per C# (I know they were suggested for Java 7, but I think they're out at the moment) you can modify them at that point.
Oh, and use Joda Time anyway :)
Jon Skeet
2010-03-09 14:28:15