Javalin – simple web framework for Java and Kotlin

Javalin is a simple web framework for Java and Kotlin.

Javalin’s main goals are simplicity, a great developer experience, and first class interoperability between Kotlin and Java.

This is free and open source software.

Features include:

  • Simple – very few concepts that you need to learn. You never extend classes and you rarely implement interfaces.
  • Lightweight – just a few thousand lines of code on top of Jetty, and its performance is equivalent to raw Jetty code. Due to its size, it’s very easy to reason about the source code
  • Interoperable – made with inter-operability in mind, apps are built the same way in both Java and Kotlin.
  • Flexible – esigned to be simple and blocking, as this is the easiest programming model to reason about. But, if you set a Future as a result, Javalin switches into asynchronous mode.
  • Supports OpenAPI with its – OpenAPI plugin, allows to generate the OpenAPI specification from the application source code.
  • Jetty – runs on top of Jetty, one of the most used and stable web-servers on the JVM. You can configure the Jetty server fully, including SSL and HTTP2 and everything else that Jetty offers.

Website: javalin.io
Support: GitHub Code Repository
Developer: David Åse and many contributors
License: Apache License 2.0

Javalin is written in Kotlin and Java. Learn Kotlin with our recommended free books and free tutorials. Learn Java with our recommended free books and free tutorials.

Return to Java Microframeworks Home Page


Popular series
Guide to LinuxNew to Linux? Read our Linux for Starters series. We start right at the basics and teach you everything you need to know to get started with Linux.
Free and Open Source SoftwareThe largest compilation of the best free and open source software in the universe. Each article is supplied with a legendary ratings chart helping you to make informed decisions.
ReviewsHundreds of in-depth reviews offering our unbiased and expert opinion on software. We offer helpful and impartial information.
Alternatives to Proprietary SoftwareReplace proprietary software with open source alternatives: Google, Microsoft, Apple, Adobe, IBM, Autodesk, Oracle, Atlassian, Corel, Cisco, Intuit, and SAS.
DockerGetting Started with Docker helps you master Docker, a set of platform as a service products that delivers software in packages called containers.
System ToolsEssential Linux system tools focuses on small, indispensable utilities, useful for system administrators as well as regular users.
ProductivityLinux utilities to maximise your productivity. Small, indispensable tools, useful for anyone running a Linux machine.
Home ComputersHome computers became commonplace in the 1980s. Emulate home computers including the Commodore 64, Amiga, Atari ST, ZX81, Amstrad CPC, and ZX Spectrum.
Now and ThenNow and Then examines how promising open source software fared over the years. It can be a bumpy ride.
Linux at HomeLinux at Home looks at a range of home activities where Linux can play its part, making the most of our time at home, keeping active and engaged.
Linux CandyLinux Candy reveals the lighter side of Linux. Have some fun and escape from the daily drudgery.
Android AppsBest Free Android Apps. We showcase free Android apps that are definitely worth downloading. There's a strict eligibility criteria for inclusion in this series.
Programming BooksThese best free books accelerate your learning of every programming language. Learn a new language today!
Programming TutorialsThese free tutorials offer the perfect tonic to our free programming books series.
Stars and StripesStars and Stripes is an occasional series looking at the impact of Linux in the USA.
Share this article

Share your Thoughts

This site uses Akismet to reduce spam. Learn how your comment data is processed.