ShortBus

ShortBus is an in-process mediator with low-friction API implemented in Java. This project is based from mhinze/ShortBus.

Setting Up

ShortBus is dependent on Spring. You'll need to configure a mediator for dependency.

@Configuration
public class MediatorConfig {
    @Bean
    public Mediator getMediator(ApplicationContext ctx) {
        return new MediatorImpl(ctx);
    }
}

Usage

ShortBus supports Request/Response messages. This dispatched to a single handler.

Request/Response

The Request/Response interface handles both command and query. First, create a message:

public class Ping implements Request<String> {

}

Then, create a handler:

@Component
public class Pong implements RequestHandler<Ping, String> {
    @override
    public String handle(Ping request) {
        return "Pong!";
    }
}

Make sure to annotate with Spring's @Component.

Invoking

To invoke each message:

@RestController
public class PingPongController {

    @AutoWired
    Mediator mediator;
    
    public String pingPong() {
        Ping ping = new Ping();
        Response<String> response = mediator.send(ping);
        return response.data; // "Pong!"
    }
}

Notification

First, create your notification message type:

public class Ping implements Notification {
    public int counter;
}

Then create your handlers for your notification:

@Component
public class Pong1 implements NotificationHandler<Ping> {
    @override
    public void handle(Ping notification) {
        notification.counter++;
    }
}

@Component
public class Pong2 implements NotificationHandler<Ping> {
    @override
    public void handle(Ping notification) {
        notification.counter++;
    }
}

Finally, publish your notification:

Ping ping = new Ping();
mediator.notify(ping); // ping.counter = 2