Java-8 Sort List of objects concerning inner object

Question

I have a List of obejcts which looks like this:

List<MyObject> myObjects = ...

and MyObject has a reference to another object MyReferencedObject. I will sort List myObjects concerning a field of MyReferencedObject called sortOrder (Integer). Is there a performant possibility to do this in a performant way?

Grzegorz Górkiewicz · Accepted Answer · 2017-04-15 08:26:36Z

1

You can either make it implement Comparable (especially if such comparison is not one-off and will be reused).

Then just call:

Collections.sort(myObjects);

Or define the order using a lambda expression:

Collections.sort(myObjects, (o1, o2) ->
      o1.getReferencedObject().getSortOrder()
      .compareTo(o2.getReferencedObject().getSortOrder()));

answered Apr 15, 2017 at 8:26

Grzegorz Górkiewicz

4,6064 gold badges24 silver badges39 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

quma Over a year ago

Thanks a lot, the second solution works for me (MyObject is compareable by another field). Thanks!

srborlongan Over a year ago

You can also use Comparator::comparing to derive a Comparator from a getter Function: Collections.sort(myObjects, Comparator.comparing(o -> o.getReferencedObject().getSortOrder()));

Collectives™ on Stack Overflow

Java-8 Sort List of objects concerning inner object

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related