How to sort an array of objects containing null elements?

Question

In my program an array fClasses of fixed length [7] of objects is created, each object is a class FClass that contains 3 Strings, an <

Answer 1

By importing the org.apache.commons.collections.comparators package of the Apache 2.1.1 Release library, I'm able to sort a list, such as an ArrayList, using the NullComparator as the second argument of the Collections.sort() method, as follows:

ArrayList list = new ArrayList();
list.add("foo");
list.add("bar");
list.add("baz");
list.add(null);

// Sort the list
Collections.sort(list, new NullComparator(true));

System.out.println(list);
// outputs:
// [bar, baz, foo, null]

The thing I like about this approach is that the NullComparator has an overload constructor which allows you to specify whether you want null to be considered a high value or a low value, which seems pretty intuitive to me.

NullComparator(boolean nullsAreHigh)

Hope this helps someone!