Why is sort method part of Collections instead of AbstractList?

Question

When sort method works upon only Lists, I feel keeping it in Collections class is somewhat buggy. Shouldn't there be a separate class dedicated to Lists? Maybe AbstractList or something like ListUtil.. ?

`sort()` could be a method of `List`. Ex: `mylist.sort()` is possible in Groovy. — jocki, Mar 16 '15 at 16:49
Do you understand the difference between `Collection` and `Collections`? — ControlAltDel, Mar 16 '15 at 16:49
Collections contains utilities for the whole collections framework, including Lists. What's the issue with that? — Louis Wasserman, Mar 16 '15 at 18:20

score 4 · Accepted Answer · answered Mar 16 '15 at 16:49

Collections is a helper class for all collections regardless of their type. In addition to method for the List there are methods specific to Maps, SortedMaps, SortedSets, and, of course, Collections.

Although making a separate helper for lists alone would be a justifiable choice, using a single helper class as a single place for all collection helpers makes perfect sense as well: it makes it easier for developers to remember where the methods are, because only one class is there.

Note that starting with Java-8 you can call sort as a default method implementation on List<T>, making the implementation even easier to locate.

Why is sort method part of Collections instead of AbstractList?

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