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Please note that DataKernel framework was massively improved and restructured into a new project named ActiveJ. Now it's even more streamlined, convenient, and powerful! We highly recommend you to migrate to ActiveJ.


DataKernel is a full-featured alternative web and big data Java framework built from the ground up. It does not use Netty, Jetty, Spring/Guice DI, RxJava, etc. Instead, it features a full application stack: Event Loop, Promises, HTTP, DI, and others, including decentralized big-data technologies and map-reduce algorithms.

No overhead of intermediate abstractions, legacy standards and third-party libraries makes the framework minimalistic, streamlined and lightning-fast!

Getting started

Just insert this snippet to your terminal...

mvn archetype:generate -DarchetypeGroupId=io.datakernel -DarchetypeArtifactId=archetype-http -DarchetypeVersion=3.1.0

... and open project in your favourite IDE. Then, build the application and run it. Open your browser on localhost:8080 to see the "Hello World" message.

To learn more about DataKernel, visit or follow our 5-minute getting-started guide.


Basic HTTP server in less than 15 lines of code:

public final class HelloWorldExample { 
    public static void main(String[] args) throws IOException {
        Eventloop eventloop = Eventloop.create();
        AsyncHttpServer server = AsyncHttpServer.create(eventloop,
                request -> Promise.of(
                                .withPlainText("Hello, World!")))

AsyncHttpServer is a built-in implementation of an HTTP server that runs asynchronously in a Node.js-inspired Event Loop.

Full-featured embedded web application server with Dependency Injection:

public final class HttpHelloWorldExample extends HttpServerLauncher { 
    AsyncServlet servlet() { 
        return request -> HttpResponse.ok200().withPlainText("Hello, World!");

    public static void main(String[] args) throws Exception {
        Launcher launcher = new HttpHelloWorldExample();

HttpServerLauncher - a predefined DataKernel Launcher that takes care of the application lifecycle and provides needed components for our server

@Provides - one of the DataKernel DI annotations

AsyncServlet - asynchronous servlet interface

Promise - Node.js-inspired async single-threaded Promises, an alternative to CompletableFuture

Lightning-fast RPC server:

public RpcServer rpcServer(Eventloop eventloop) {
    return RpcServer.create(eventloop)
            .withHandler(Integer.class, Integer.class, req -> Promise.of(req * 2));


See the docs, examples, and tutorials on our website.

Need help or found a bug?

Feel free to open a GitHub issue.