SvenWoltmann / virtual-threads-spring

Spring demo application to compare controllers using CompletableFuture vs. virtual threads.

Virtual Threads Spring Demo

This repository contains a Spring demo application using "Virtual Threads", a feature described in JEP 444 and released in Java 21.

The application has two controllers:

• ControllerEvolution1_Sequential: sequential code on platform threads or virtual threads
• ControllerEvolution2_CompletableFuture: asynchronous code using CompletableFuture

Start the application in dev mode using:

mvn spring-boot:run

Then query the endpoints using:

curl localhost:8080/stage1-seq/product/1
curl localhost:8080/stage2-cf/product/1

To switch to virtual threads, uncomment the two bean definitions in SpringVirtualThreadTestApplication.java, then access this endpoint again:

curl localhost:8080/stage1-seq/product/1

Within IntelliJ, you can also open the endpoints-test.http file to run the HTTP requests.

Java 21 IDE Support

IntelliJ IDEA supports Java 21 as of version 2023.2.2. As long as this version is not yet released, you can install the release candidate via the JetBrains Toolbox App by going into the IntelliJ IDEA settings and activating the "Early Access Program".

Java Downloads

You can download Java 21 from here: https://jdk.java.net/21/

To install multiple Java versions on Linux or macOS, I recommend using SDKMAN!

To install multiple Java versions on Windows, have a look at this tutorial: How to Change Java Versions in Windows

Other Java 21 Examples

You might also find these GitHub repositories interesting:

Virtual Threads:

• https://github.com/SvenWoltmann/virtual-threads
• https://github.com/SvenWoltmann/virtual-threads-quarkus

Structured Concurrency:

• https://github.com/SvenWoltmann/scoped-values

Scoped Values:

• https://github.com/SvenWoltmann/scoped-values

Pattern Matching for Switch:

• https://github.com/SvenWoltmann/pattern-matching-for-switch