Java's Project Loom & Co

The end for reactive programming?

These are the code examples for my talk at the WeAreDevelopers World Congress 2024.

This repository contains 4 maven projects of runnable code that are described in more detail in the following sections.

• For three of these projects you need to set your JAVA_HOME environment variable to a version 17 JDK.
• For one these projects you need to set your JAVA_HOME environment variable to a version 21 JDK.
• You also need Maven to run the projects.

You can run the projects from the command line as described below. Alternatively, you can run them from your favorite IDE.

JDK 17 Blocking Code Example

This code example is meant to run faulty and it will break because the JVM will run out of memory because too many threads are created.

In the directory jdk17-blocking you will find the Java class Main.java. This class contains the main implementation for this example.

This maven project needs to run with a JAVA_HOME variable pointing to a version 17 JDK.

$> cd jdk17-blocking
$> export JAVA_HOME=/Users/my_user/Library/Java/JavaVirtualMachines/openjdk-17.0.5/Contents/Home/
$> mvn clean compile exec:java

JDK 17 Reactive Code Example

This code example is meant to run successfully by using the reactive framework Spring WebFlux.

In the directory jdk17-reactive you will find the Java class Main.java. This class contains the main implementation for this example.

This maven project needs to run with a JAVA_HOME variable pointing to a version 17 JDK.

$> cd jdk17-reactive
$> export JAVA_HOME=/Users/my_user/Library/Java/JavaVirtualMachines/openjdk-17.0.5/Contents/Home/
$> mvn clean compile exec:java

JDK 17 Kotlin Coroutines Code Example

This code example is meant to run successfully by using the Kotlin Coroutines.

In the directory kotlin-jdk-17 you will find the Kotlin class Main.kt. This class contains the main implementation for this example.

This maven project needs to run with a JAVA_HOME variable pointing to a version 17 JDK.

$> cd kotlin-jdk-17
$> export JAVA_HOME=/Users/my_user/Library/Java/JavaVirtualMachines/openjdk-17.0.5/Contents/Home/
$> mvn clean compile exec:java

JDK 21 Java Code Example

This code example is meant to run successfully by using Java 21 Virtual Threads.

In the directory jdk21-vt you will find the Java class Main.java. This class contains the main implementation for this example.

This maven project needs to run with a JAVA_HOME variable pointing to a version 21 JDK.

$> cd jdk21-vt
$> export JAVA_HOME=/Users/my_user/Library/Java/JavaVirtualMachines/openjdk-21.0.2/Contents/Home/
$> mvn clean compile exec:java

License

Copyright [2024] [Holisticon AG]

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.