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 ⎯⎯⎯⎯⎯⎯
◦ JEP 431: Sequenced Collections ➱ https://openjdk.org/jeps/431
◦ Inside Java Newscast #50 on JDK 21: https://youtu.be/qGaUZ1Z34jw
◦ Inside Java Newscast #45 on Sequenced Collections: https://youtu.be/9G_0el3RWPE
◦ Dev.java ➱ https://dev.java
◦ Inside.java ➱ https://inside.java
◦ JDK 21 ➱ https://openjdk.org/projects/jdk/21
◦ OpenJDK ➱ https://openjdk.org
◦ Oracle Java ➱ https://www.oracle.com/java/

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