Java After Eleven

Nicolai Parlog

nipafx.dev / @nipafx

JavaOne

@JavaOne

Developer Advocate

Java Team at Oracle

Lots to talk about

The plan for today:

  • start with a Java 11 code base

  • take it all the way to Java 19
    (and beyond)

  • be amazed by how much changes

This talk is:

  • a showcase, not a tutorial

  • not a complete list

  • created with the lavish help
    of the people in Twitch chat

Links

Java 11

  • released 09/2018

  • free support by Oracle ended 01/2019

  • free community support until 10/2024

  • more free and commercial support available

It’s a great release…​

  • first "modern" Java release with LTS

  • solid feature set

  • stable

  • great support

…​but better things are waiting

Java 11 misses out on many recent developments:

  • thrilling new language features

  • some improved APIs

  • a few new JVM features

  • improved performance

Curious?

Let me show you how much
you’re missing out on
if you’re (still?) on Java 11.

Code

Code, code, code, code

(code base)

Java 12

What we’ve seen:

  • more powerful collections | Collectors::teeing

  • better async error handling | ↴
    CompletableFuture::exceptionallyCompose

Java 12

What we haven’t seen:

  • transforming Strings | ↴
    String.transform(Function<String, R>)

  • social media number format | ↴
    NumberFormat::getCompactNumberInstance

  • easy file comparison | Files::mismatch

  • included JDK CDS archive

Java 13

What we haven’t seen:

  • automatic application CDS archive

Java 14

What we’ve seen:

  • switch expressions | ↴

    boolean bool = switch (ternaryBool) {
	case TRUE -> true;
	case FALSE -> false;
	case FILE_NOT_FOUND -> throw
			new FileNotFoundException("🤬");
};

  • helpful NPE messages

Java 14

What we haven’t seen:

  • JFR event streaming

Java 15

What we’ve seen:

  • text blocks | ↴

    var recommendation = """
		{
			"title": '$TITLE',
			"recommendations": $RECS
		}
	""";

  • obvious String formatting | String::format

Java 15

What we haven’t seen:

  • hidden classes

Java 16

What we’ve seen:

  • records | record Title(String text)

  • type patterns | o instanceof Article a

  • Stream::toList

Java 16

What we haven’t seen:

  • improvements to Stream and HTTP/2 client

  • Unix domain socket support

  • OS-specific installers | jpackage

Java 17

What we’ve seen:

  • sealed clases | sealed class …​ permits

  • enhanced pseudo-random number generator API | ↴
    RandomGenerator and RandomGeneratorFactory

Java 17

What we haven’t seen:

  • always-strict floating-point semantics

Java 17

What we’ve seen a bit:

  • better performance characteristics

All following diagrams come
from Stefan Johansson's post
GC progress from JDK 8 to JDK 17.

Java 18

What we’ve seen:

  • JavaDoc code snippets (better)

  • jwebserver

  • UTF-8 by default

Java 18

What we haven’t seen:

  • Internet resolution SPI

Java 19

Previews galore!

Java Next

What we’ve seen:

  • pattern matching in switch | ↴

    return switch (post) {
	case Article article -> article.repository();
	case Video video -> video.repository();
	default -> Optional.empty();
};

  • record patterns | ↴

    case Article(var repository) -> repository;

Java Next

What we’ve seen:

  • virtual threads + structured concurrency | ↴

    try (var scope = new StructuredTaskScope
		.ShutdownOnFailure()) {
	// ...

	scope.join();
	scope.throwIfFailed();
} catch (/* ... */) {
	// ...
}

Java Next

What we haven’t seen

Java 11 to 19+

  • more expressive code | LOC: 2061 📉 1663

  • faster code | run time: ~ 1.1 s 📉 ~ 0.9 s

  • better JVM | GCs, packaging, monitoring, etc.

  • better tooling | JFR, JavaDoc, jwebserver, etc.

Sure you don’t want to upgrade?

So long…​

37% off with
code fccparlog

bit.ly/the-jms

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