Java 21 & Beyond

Java 21 (LTS) introduces game-changing features for concurrency and productivity.

Virtual Threads (Project Loom)

Lightweight threads that dramatically reduce the effort of writing high-throughput concurrent applications.

try (var executor = Executors.newVirtualThreadPerTaskExecutor()) {
    IntStream.range(0, 10_000).forEach(i -> {
        executor.submit(() -> {
            Thread.sleep(Duration.ofSeconds(1));
            return i;
        });
    });
}

Benefits:

• Create millions of threads
• Blocking code is cheap
• No need for complex reactive programming

Sequenced Collections

Unified interface for collections with a defined encounter order.

SequencedCollection<String> list = new ArrayList<>();
list.addFirst("First");
list.addLast("Last");
System.out.println(list.getFirst());
System.out.println(list.getLast());

Record Patterns

Enhances pattern matching to deconstruct records.

record Point(int x, int y) {}

Object obj = new Point(10, 20);

if (obj instanceof Point(int x, int y)) {
    System.out.println("X: " + x + ", Y: " + y);
}

Pattern Matching for Switch

Object obj = "Hello";

String result = switch (obj) {
    case Integer i -> "Integer: " + i;
    case String s -> "String: " + s.toUpperCase();
    case null -> "It is null";
    default -> "Unknown";
};

String Templates (Preview)

String interpolation in Java!

String name = "Java";
String info = STR."Hello \{name}";

Quiz