Java - Vert.X Framework

About

Vert.x is not a framework but a toolkit: the core library defines the fundamental APIs for writing asynchronous networked applications, and then you can pick the useful modules for your application (e.g., database connection, monitoring, authentication, logging, service discovery, clustering support, etc).

Vert.x:

is based on the Netty project.
implements the reactor pattern (ie event loop), event-driven, reactive, non-blocking
is a polyglot framework

Usage

high volume message
event processing,
micro-services,
API gateways,
HTTP APIs for mobile applications,
etc

Concept

Three concepts:

Vertx - The core instance that allows:
- high availability (HA) support. ¹⁾
- reference to the event bus,
- setting timers,
- calls the handlers using the event loop thread (Reactor pattern)
verticle - the actors deployed on Vertx
event bus - the bus that allows verticles to communicate

App

Verticle

package examples.vertx;

import io.vertx.core.AbstractVerticle;
import io.vertx.core.Future;

public class MyVerticle extends AbstractVerticle {

    @Override
    public void start(Future<Void> startFuture) {
        System.out.println("MyVerticle started!");
    }

    @Override
    public void stop(Future stopFuture) throws Exception {
        System.out.println("MyVerticle stopped!");
    }

}

Main

import io.vertx.core.Vertx;

public class VertxApp {

    public static void main(String[] args) {
        Vertx vertx = Vertx.vertx();
        vertx.deployVerticle(new MyVerticle());
    }

}

¹⁾

Vertx HA