EventSystem

A blazing-fast event bus for Java.

Requirements

Java 17 or higher

Installation

In your build.gradle:

plugins {
    // Required if you want to use Listener object.
    id 'io.github.stanikoc.eventsystem.injector' version '1.0.0'
}

dependencies {
    implementation 'io.github.stanikoc:eventsystem-impl:1.0.0'
}

Quick Start

Getting started takes only a few lines of code.

1. Define an Event

package com.example;

// It can be any object, but records are preferred due to a better lookup time.
public record ResultEvent(long result) {} //

2. Create a Subscriber

Create a class that extends SubscriberImpl. That class holds all the listeners.

package com.example;

import io.github.stanikoc.eventsystem.SubscriberImpl;
import io.github.stanikoc.eventsystem.Listener;

public class ResultService extends SubscriberImpl { //
    public ResultService() {
        // The generic type <ResultEvent> is automatically resolved at compile time
        listen(new Listener<ResultEvent>() {
            @Override
            public void onEvent(ResultEvent event) {
                System.out.println("The result is: " + event.result());
            }
        });

        // Alternatively, one may make a normal class, not necessarily an anonymous one.
        listen(new ResultListener());

        // Or use a lambda method
        listen(ResultEvent.class, e -> {});
    }

    private static final class ResultListener extends Listener<ResultEvent> {
        @Override
        public void onEvent(ResultEvent event) {
            // Your logic here
        }
    }
    
}

3. Register and Post

Instantiate your EventBus, register your subscriber, and start dispatching events.

package com.example;

import io.github.stanikoc.eventsystem.EventBus;
import io.github.stanikoc.eventsystem.EventBusImpl;

public class Main {
    private static final EventBus eventBus = new EventBusImpl(); //

    public static void main(String[] args) {
        // Register the subscriber
        eventBus.subscribe(new ResultService());

        // Post an event to all active listeners!
        eventBus.post(new ResultEvent(42));
    }
}