Again, to use Collections.sort, you need one of these to be true: The type must be Comparable (use the 1-arg sort) A Comparator for the type must be provided (use the 2-args sort) When to use …

Apr 21, 2013 · To use the Comparator interface you have to implement it and pass it as an anonymous class to Collections.sort (List list, Comparator c) as the second parameter.

Mar 20, 2022 · Comparator.comparing(Function<? super T, ? extends U> key) returns a Comparator<T> that compares by that sort key. The main difference is that compare method provides a single point …

Mar 9, 2011 · Here it is not sort by alphabetic order. I want to use my custom sorting order like Red car come first, then Blue, etc. For that I try to use Java Comparator and Comparable but it allows to sort …

Feb 15, 2010 · Use Comparable if you want to define a default (natural) ordering behaviour of the object in question, a common practice is to use a technical or natural (database?) identifier of the object for …

Mar 25, 2009 · Use the constructor overload which takes a Comparator<? super E> comparator and pass in a comparator which compares in the appropriate way for your sort order. If you give an …

This can easily be done using Java 8 and the use of a reversed Comparator. I have created a list of files from a directory, which I display unsorted, sorted and reverse sorted using a simple Comparator for …

Comparator provides a way for you to provide custom comparison logic for types that you have no control over. Comparable allows you to specify how objects that you are implementing get compared. …

Oct 7, 2015 · I use for it java.util.stream.Stream.sorted(Comparator) method. Here is a description according Java API: Returns a stream consisting of the elements of this stream, sorted according to …

For example, a Comparator<Dog> to sort Dog instances descending by age could be created with the following: Comparable.comparingToInt(Dog::getDogAge).reversed(); The function take a lambda …