How Fast Can You Java?

Photo of Luqman Saeed by Luqman Saeed

The Java Platform, over the years, has shown how resilient and reliable a development platform it is. Of course, as developers, we always want to see how fast we can execute our code. Well, now you have the chance to find out, or actually prove how fast Java is. Gunnar Morling, Software Engineer at Decodable has a very exciting Java warmup game for us all. He calls it the One Billion Row Challenge. Huh? Yup. Let's hear it from him.

"Your mission, should you decide to accept it, is deceptively simple: write a Java program for retrieving temperature measurement values from a text file and calculating the min, mean, and max temperature per weather station. There’s just one caveat: the file has 1,000,000,000 rows!"

At its heart, this challenge is a test of Java's true potential. You're tasked to leverage the core strength of Java Standard Edition, without any third-party libraries, to create the swiftest possible program for reading and processing this massive file.

The rules of the game are quite simple:

  1. Any submission must be written in Java
  2. Any Java distribution available through SDKMan as well as early access builds from may be used, including EA builds for OpenJDK projects like Valhalla.
  3. No external dependencies may be used.

Head over to his blog post linked above to see how to enter the contest. How far can you push vanilla Java SE with all the latest constructs like virtual threads added lately? Join in the fun and let's find out. There are already some incredible entries with mind blowing speeds on the leaderboard. Ready to show the world how fast you can Java? Let the coding begin! 🚀👩‍💻👨‍💻