Java 21 New Feature: Sequenced Collections - JEP Cafe #19

Learn the principles of the Sequenced Collections, Sets, and Maps, a new feature introduced in JDK 21.

Sequenced Collections are about modelling collections with a defined encounter order, giving you direct access to their first and last element. Learn about the new Sequenced Collections API, part of the Collections Framework, introduced in JDK 21.

⎯⎯⎯⎯⎯⎯ Chapters ⎯⎯⎯⎯⎯⎯
0:00 Intro
1:19 Introducing the architecture of the Collections API
2:38 What does it mean for a collection to be sorted
3:46 Ordering elements in a collection with an index
4:53 Differences between Lists and SortedSets
5:22 Defining the encounter order for List, Set, and SortedSet
8:10 Properties of LinkedHashSet
9:09 Common behavior between List, SortedSet and LinkedHashSet
9:58 Defining the behavior of sequenced collections
12:10 Adding SequencedCollection and SequencedSet to the Collections API
13:27 Making Deque implement SequencedCollection
15:41 Iterating over the elements of a Map
17:18 Iterating over the elements of a SortedMap or NavigableMap
18:06 Introducing SequencedMap
19:06 Creating unmodifiable views with the Collections factory class
19:16 Outro

⎯⎯⎯⎯⎯⎯ Resources ⎯⎯⎯⎯⎯⎯

Tags: #Java #Java21 #OpenJDK #JDK #JDK21 #Collection #JEPCafe #insidejava

[rashimpathak]

wondefully explianed.. always wait for your new videos... thx a lot and our best wishes to you

[christianschafer]

Sequenced Collections starting at 9:10.
Overall I'd like to see more diagrams and code. Too much information just over audio. This is not a podcast, is it?

[kubarurak]

6:18 why shouldnt you use linkedlists?

[chrisschaefer]

quite sly to manage to finish your coffee at the end of the talk, I was following that from about 1/2 way through thinking it might be the case. well done.

[klarissaclairiton]

Merci. Tout a été bien expliqué en anglais.

[olivierboisse]

Why doesn't Queue extend SequencedCollection interface ?

[pablon]

Maybe I'm not getting it well. Because I don't agree when in 8:30 Jose says "Does it have all the properties of List? Not quite. Can you get the third element for instance, that is an element from an index? The answer is yes. Could you remove and element at a given index? The answer is still yes"
I mean, with a LinkedHashSet you cannot get an element given its index.

[akirsch]

Why should LinkedList not be used anymore? It is the fastest data structure for random inserts because the following objects do not have to be moved after insertion. For the price that random access is slow.

[AhmetMurati]

I have not being using LinkedList since years on. I have found also a bug in Java 8 about currency format for Kosova and it is fixed in Oracle Java 8 and newer versions and also at OpenJDK 8 and newer versions.

[IIIxwaveIII]

is it possible that this JEP makes the collections framework more confusing and cumbersome then it is?

[DF-ssep]

Coffee is for closers. Go back to your cubicle and finish reviewing the PR.

[superdupe]

quite the cynical and grumpy crowd in the comments section

[softdev]

It will be good if s.o.p changes to print and no "new" keyword

[szaboaz]

"Feeling like taking a coffee break? So do I." English is not my first language, but shouldn't that be "So am I."? Grammar "not see" off.

[sanaullahsianch]

if someone starts learning from latest release of java until he finishes learning java there will be at least two new releases of java then he continue to learn relevant technologies used in web like spring framework or again learn latest releases, its better to give up on java and learn python or some other languages