Java 21 - a peek inside

  • Besides virtual threads, is there anything else interesting in Java 21? What should you be looking forward to? Our e-book has the answers!

Java 21

Adrian Michalski
An overview of what's new in Java 21 and a review of the key features.
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Take a look, Java enthusiast, and see what's inside!

We encourage you to download our e-book, which provides a detailed description of the latest features and improvements in Java 21. Here’s a brief overview of the contents:


Virtual Threads

What benefits does the introduction of virtual threads bring in terms of managing concurrency? Does Project Loom truly reduce time and memory costs?


Scoped Values (Preview)

Do Scoped Values offer greater control over shared values in threads? Can they be more efficient than ThreadLocal?


Structured Concurrency (Preview)

How does Structured Concurrency make it easier to manage subtasks and improve application stability? Does it reduce response time by better error management?


Sequenced Collections

How do new interfaces like SequencedCollection, SequencedSet, and SequencedMap affect the management of element order? Can they increase consistency and predictability in data management?


Pattern Matching for switch

What benefits does enhanced pattern matching in switch statements bring? Does the code become more readable and concise?


Record Patterns

Does record destructuring in switch statements truly simplify access to components? What opportunities does matching nested records offer?


Unnamed Patterns and Variables

What are the advantages of using anonymous variables (_) in code? Does it simplify exception handling and iteration?


Unnamed Classes and Instance Main Methods

What capabilities do unnamed classes and instance main methods offer in Java? Do they simplify the creation of simple applications?


String Templates

Do the new String Templates really make text formatting easier? How does Java 21 integrate text templates with expressions?


Foreign Function & Memory API

What benefits does Project Panama bring in terms of JVM communication with native libraries? Does the new API improve memory control?


Vector API

How does the Vector API increase application performance? Can parallel data operations improve efficiency through vector operations?


Download the e-book to discover answers to these and other questions about the new features in Java 21!

Author of the ebook


I am a programmer with extensive experience in solving problems in the telecom and financial sectors.

I primarily work with JVM family languages and JavaScript, but I also enjoy occasionally delving into C and Assembly.

On a personal note, I am a father, and in my limited free time, I like to create – from music and drawings to electronics.

Adrian Michalski

What do the experts say about the ebook?

  • In the fast-paced world of IT, where novelties emerge quicker than if they were generated by ChatGPT itself, Adrian Michalski's book on the latest features of Java 21 serves as an outstanding guide for anyone keen on understanding and effectively harnessing these changes. With remarkable precision, Adrian delves into each novelty introduced in this update, focusing on the so-called "meat" and employing a precise, technical yet highly engaging language that ensures clarity of communication.

    Jacek Feliksiak

    Senior Java Developer at j‑labs
  • After reading Adrian's ebook, I am fully aware of what has been introduced in Java 21 and how individual features operate, and most importantly, how to use them in practice. The simplicity in explaining even the most complicated topics and their application deserves praise. It's great to see features included even though they are still in the preview phase but definitely worth noting. The chapter on String Templates is particularly extensive and includes a superb example with SQL!

    Adrian Długosz

    Senior Java Developer at j‑labs