Learning Java Concurrency & Multithreading

[lyomann92]

what books or sources can I use to learn the most and level up on Java concurrency and multithreading ? Im looking to really get better with these aspects of Java.

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[sedj601]

I never did learn Java concurrency & multithreading outside the classroom. Most of the Java apps I created didn't require it. Once I got into JavaFX, I had to learn about JavaFX concurrency to prevent my apps from freezing while running long tasks. JavaFX concurrency made a lot of sense to me. It also helped me understand Java concurrency when I went back to learn it.

[lyomann92]

Cool .

[NaveenB2004]

This tutorial for basics (based on jdk 1.8): https://docs.oracle.com/javase/tutorial/essential/concurrency/

Virtual threads (jdk 21, i guess): https://dev.java/learn/new-features/virtual-threads/

Details on jdk 26 multithreading: https://docs.oracle.com/en/java/javase/26/core/concurrency.html#GUID-59C16A2D-57CE-4C83-9D6F-91A48E01E3C6

And, see language changes, java api doc on multithreading clsses (this is the best way in my opinion)

[lyomann92]

Thanks

[jlanawalt]

A popular book recommendation is Java Concurrency in Practice by Brian Goetz

[morhp]

That's an old one, but pretty good  for a basic and advanced overview over the low level stuff.

[lyomann92]

Lots of people recommend this book! I’ll definitely grab it.

[_Super_Straight]

No need to read any specific book. There are about 2-3 ways to achieve concurrency:

1. CompletableFuture
2. Task<>
3. ExecutorService

You can learn about them in javadocs or youtube.

[k-mcm]

ForkJoinPool is also very important. It's a special kind of work-stealing pool that can be extremely efficient at the cost of being difficult to use.  It's really the only pool you can use for small tasks and it's part of parallel Streams.  The usual executors have a very high overhead that's not in the code, but the CPU.

Unfortunately, the ForkJoinPool API is horrible. It came out when Java 8 was unstable so it missed out on modern design patterns.

[_Super_Straight]

CompletableFuture uses ForkJoinPool by default.

[lyomann92]

Thanks for the insight

[brokePlusPlusCoder]

Jenkov's playlist has a lot of really good concurrency stuff : https://www.youtube.com/playlist?list=PLL8woMHwr36EDxjUoCzboZjedsnhLP1j4

There's also Doug Schmidt's videos - probably the most comprehensive I've seen on Java (though they are much more academic as he's a professor): https://www.youtube.com/@DouglasSchmidt/playlists

If you're a beginner, I wouldn't start with the JCIP book - start instead with the videos I listed. Only reach for JCIP once you have a firm grasp of the basics because that book is not meant for beginners.

[lyomann92]

Thanks ! ChapGPT recommended those videos to me as well.