Leanpub Header

Skip to main content
Go to Leanpub.com

From Java 17 to Java 21

Upgrade to Java 21 LTS from Java 17 LTS

Fu Cheng

Features and changes from Java 17 to Java 21. Record patterns, pattern matching for switch, virtual threads, structured concurrency, Foreign Function & Memory API.

Minimum price

$10.00

$15.00

You pay

$15.00

Author earns

$12.00
$

...Or Buy With Credits!

You can get credits with a paid monthly or annual Reader Membership, or you can buy them here.
PDF
EPUB
127
Pages
About

About

About the Book

Java 25 is released. Check out my new book From Java 21 to 25 to upgrade to Java 25.

Upgrade to Java 21 to use virtual threads.

Changes from Java 17 LTS to Java 21 LTS, including updates in Java 18, 19, 20 and 21.

Content included in the book:

  • Pattern matching
  1. Record patterns
  2. Pattern matching for switch
  3. Unnamed patterns and variables
  • Multi-threading
  1. Virtual threads
  2. Structured concurrency
  3. Scoped values
  • Standard library changes
  1. UTF-8 by default
  2. Internet-address resolution SPI
  3. Simple web server
  4. Sequenced collections
  5. Key Encapsulation Mechanism API
  • Java languages
  1. String templates
  2. Code snippets in Java API documentation
  3. Unnamed classes and instance main methods
  • Panama project
  1. Foreign Function & Memory API
  2. Vector API

If you are currently using Java 11 LTS, check out another book From Java 11 to 17.

Share this book

Categories

Java

Feedback

Email the Author

Bundles

Bundles that include this book

Author

About the Author

Fu Cheng

Full-stack software developer and content creator.

Contents

Table of Contents

Introduction

  1. JEPs in Different Java Releases
  2. Install Java 21
  3. Build Tools
  4. Source Code
  5. Java Language

String Templates

  1. Template Expressions
  2. String Template
  3. Template Processor
  4. SMS Message Template
  5. Format Processor

Unnamed Classes and Instance Main Methods

  1. Java Program Launch Protocol
  2. Unnamed Classes

Code Snippets in Java API Documentation

  1. Inline Snippets
  2. External Snippets
  3. Markup Tags
  4. Tag References

Pattern Matching

  1. Record Patterns
  2. Pattern Matching for switch
  3. Unnamed Patterns and Variables
  4. Core Library

UTF-8 By Default

Internet-Address Resolution SPI

Simple Web Server

Sequenced Collections

  1. SequencedCollection
  2. SequencedSet
  3. SequencedMap
  4. Classes Hierarchy

Reimplement Core Reflection with Method Handles

Key Encapsulation Mechanism API

  1. Multi-threading

Virtual Threads

  1. Create Virtual Threads
  2. Virtual Threads Basics
  3. Thread-local Variables
  4. Scheduling of Virtual Threads
  5. Execution of Virtual Threads
  6. ExecutorService
  7. Debugging

Structured Concurrency

  1. Basic Usage
  2. invokeAll
  3. invokeAny
  4. Shutdown and Close of StructuredTaskScope

Scoped Values

  1. Project Panama

Foreign Function & Memory API

  1. Foreign Memory
  2. Memory Segments
  3. Arenas
  4. Dereferencing Memory Segments
  5. Memory Layouts
  6. Dereferencing Memory Layouts
  7. More About Arenas
  8. Foreign Functions

Vector API

  1. API Basics
  2. Euclidean Distance Calculation
  3. JVM

Generational ZGC

Prepare to Disallow the Dynamic Loading of Agents

  1. Deprecated & Removed Features

Deprecated Features

  1. Finalization
  2. Windows 32-bit x86 Port
  3. Miscellaneous

Linux/RISC-V Port

Annotation Processing

Get the free sample chapters

Click the buttons to get the free sample in PDF or EPUB, or read the sample online here

Download Sample PDFDownload Sample EPUBRead Sample OnlineRead online

The Leanpub 60 Day 100% Happiness Guarantee

Within 60 days of purchase you can get a 100% refund on any Leanpub purchase, in two clicks.

Now, this is technically risky for us, since you'll have the book or course files either way. But we're so confident in our products and services, and in our authors and readers, that we're happy to offer a full money back guarantee for everything we sell.

You can only find out how good something is by trying it, and because of our 100% money back guarantee there's literally no risk to do so!

So, there's no reason not to click the Add to Cart button, is there?

See full terms...

Earn $8 on a $10 Purchase, and $16 on a $20 Purchase

We pay 80% royalties on purchases of $7.99 or more, and 80% royalties minus a 50 cent flat fee on purchases between $0.99 and $7.98. You earn $8 on a $10 sale, and $16 on a $20 sale. So, if we sell 5000 non-refunded copies of your book for $20, you'll earn $80,000.

(Yes, some authors have already earned much more than that on Leanpub.)

In fact, authors have earned over $14 million writing, publishing and selling on Leanpub.

Learn more about writing on Leanpub

Free Updates. DRM Free.

If you buy a Leanpub book, you get free updates for as long as the author updates the book! Many authors use Leanpub to publish their books in-progress, while they are writing them. All readers get free updates, regardless of when they bought the book or how much they paid (including free).

Most Leanpub books are available in PDF (for computers) and EPUB (for phones, tablets and Kindle). The formats that a book includes are shown at the top right corner of this page.

Finally, Leanpub books don't have any DRM copy-protection nonsense, so you can easily read them on any supported device.

Learn more about Leanpub's ebook formats and where to read them

Write and Publish on Leanpub

You can use Leanpub to easily write, publish and sell in-progress and completed ebooks and online courses!

Leanpub is a powerful platform for serious authors, combining a simple, elegant writing and publishing workflow with a store focused on selling in-progress ebooks.

Leanpub is a magical typewriter for authors: just write in plain text, and to publish your ebook, just click a button. (Or, if you are producing your ebook your own way, you can even upload your own PDF and/or EPUB files and then publish with one click!) It really is that easy.

Learn more about writing on Leanpub