Java 21 New Feature: Sequenced Collections

This course explains sequenced collections in Java 21, including how lists, sets, and maps define encounter order and expose their first and last elements. It covers the related Collections API interfaces and their behavior.

Syllabus

Intro
Introducing the architecture of the Collections API
What does it mean for a collection to be sorted
Ordering elements in a collection with an index
Differences between Lists and SortedSets
Defining the encounter order for List, Set, and SortedSet
Properties of LinkedHashSet
Common behavior between List, SortedSet and LinkedHashSet
Defining the behavior of sequenced collections
Adding SequencedCollection and SequencedSet to the Collections API
Making Deque implement SequencedCollection
Iterating over the elements of a Map
Iterating over the elements of a SortedMap or NavigableMap
Introducing SequencedMap
Creating unmodifiable views with the Collections factory class
Outro