README.md

Project Loom Experiment using Spring Boot, Spring WebMVC, and Postgres

This repository contains an experiment that uses a Spring Boot application with Virtual Threads.

Involved components:

• Spring Framework 6.0 M5
• Spring Boot 3.0 M4
• Apache Tomcat 10.1.0 M17
• HikariCP 5.0.1 (Loom issue: brettwooldridge/HikariCP#1463)
• PGJDBC 42.4.0 (PR that turns synchronized into Loom-friendly Locks: pgjdbc/pgjdbc#1951)

This experiment evolves incrementally, find the previous state at https://github.com/mp911de/spring-boot-virtual-threads-experiment/tree/boot-2.4.

You need Java 19 (EAP) with --enable-preview to run the example.

Customization of a vanilla Spring Boot with Tomcat application:

@Bean
AsyncTaskExecutor applicationTaskExecutor() {
    // enable async servlet support
    ExecutorService executorService = Executors.newVirtualThreadPerTaskExecutor();
    return new TaskExecutorAdapter(executorService::execute);
}

@Bean
TomcatProtocolHandlerCustomizer<?> protocolHandlerVirtualThreadExecutorCustomizer() {

    return protocolHandler -> {
        protocolHandler.setExecutor(Executors.newVirtualThreadPerTaskExecutor());
    };
}

After starting the application, run GET http://localhpst:8080/where-am-i to verify you're running on a virtual thread:

$ http :8080/where-am-i                                      
HTTP/1.1 200 
Connection: keep-alive
Content-Length: 51
Content-Type: text/plain;charset=UTF-8
Date: Wed, 27 Jul 2022 09:34:23 GMT
Keep-Alive: timeout=60

VirtualThread[#82]/runnable@ForkJoinPool-1-worker-1

License

• Apache License 2.0