Inprocess Event Listener using Eventbux
Yes, you can implement event-driven architecture with other frameworks as well. Here are a few examples using different frameworks:
### 1. **Google Guava EventBus**
Google Guava provides an `EventBus` for event-driven programming. Here is how you can use it:
1. **Add Dependency**:
```xml
```
2. **Define an Event Class**:
```java
public class CustomObjectChangeEvent {
private final String message;
public CustomObjectChangeEvent(String message) {
this.message = message;
}
public String getMessage() {
return message;
}
}
```
3. **Set up EventBus**:
```java
import com.google.common.eventbus.EventBus;
import com.google.common.eventbus.Subscribe;
public class EventBusExample {
public static void main(String[] args) {
EventBus eventBus = new EventBus();
CustomObjectChangeListener listener = new CustomObjectChangeListener();
eventBus.register(listener);
CustomObjectChangePublisher publisher = new CustomObjectChangePublisher(eventBus);
publisher.publishEvent("Change 1");
publisher.publishEvent("Change 2");
publisher.publishEvent("Change 3");
}
public static class CustomObjectChangeListener {
@Subscribe
public void handleCustomObjectChangeEvent(CustomObjectChangeEvent event) {
System.out.println("Received event: " + event.getMessage());
}
}
public static class CustomObjectChangePublisher {
private final EventBus eventBus;
public CustomObjectChangePublisher(EventBus eventBus) {
this.eventBus = eventBus;
}
public void publishEvent(String message) {
eventBus.post(new CustomObjectChangeEvent(message));
}
}
}
```
### 2. **Akka**
Akka is a toolkit and runtime for building highly concurrent, distributed, and resilient message-driven applications on the JVM.
1. **Add Dependency**:
```xml
```
2. **Define Actor and Messages**:
```java
import akka.actor.AbstractActor;
import akka.actor.ActorRef;
import akka.actor.ActorSystem;
import akka.actor.Props;
public class AkkaExample {
public static void main(String[] args) {
ActorSystem system = ActorSystem.create("event-system");
ActorRef listener = system.actorOf(Props.create(CustomObjectChangeListener.class), "listener");
ActorRef publisher = system.actorOf(Props.create(CustomObjectChangePublisher.class, listener), "publisher");
publisher.tell(new CustomObjectChangeEvent("Change 1"), ActorRef.noSender());
publisher.tell(new CustomObjectChangeEvent("Change 2"), ActorRef.noSender());
publisher.tell(new CustomObjectChangeEvent("Change 3"), ActorRef.noSender());
system.terminate();
}
public static class CustomObjectChangeEvent {
private final String message;
public CustomObjectChangeEvent(String message) {
this.message = message;
}
public String getMessage() {
return message;
}
}
public static class CustomObjectChangeListener extends AbstractActor {
@Override
public Receive createReceive() {
return receiveBuilder()
.match(CustomObjectChangeEvent.class, event -> {
System.out.println("Received event: " + event.getMessage());
})
.build();
}
}
public static class CustomObjectChangePublisher extends AbstractActor {
private final ActorRef listener;
public CustomObjectChangePublisher(ActorRef listener) {
this.listener = listener;
}
@Override
public Receive createReceive() {
return receiveBuilder()
.match(CustomObjectChangeEvent.class, event -> {
listener.tell(event, getSelf());
})
.build();
}
}
}
```
### 3. **Vert.x EventBus**
Vert.x provides an event bus for event-driven programming. Here is how you can use it:
1. **Add Dependency**:
```xml
```
2. **Set up Vert.x**:
```java
import io.vertx.core.AbstractVerticle;
import io.vertx.core.Vertx;
import io.vertx.core.eventbus.EventBus;
import io.vertx.core.eventbus.Message;
public class VertxExample {
public static void main(String[] args) {
Vertx vertx = Vertx.vertx();
EventBus eventBus = vertx.eventBus();
vertx.deployVerticle(new CustomObjectChangeListener());
vertx.deployVerticle(new CustomObjectChangePublisher());
eventBus.publish("custom.object.change", "Change 1");
eventBus.publish("custom.object.change", "Change 2");
eventBus.publish("custom.object.change", "Change 3");
}
public static class CustomObjectChangeListener extends AbstractVerticle {
@Override
public void start() {
vertx.eventBus().consumer("custom.object.change", this::handleCustomObjectChangeEvent);
}
private void handleCustomObjectChangeEvent(Message
System.out.println("Received event: " + message.body());
}
}
public static class CustomObjectChangePublisher extends AbstractVerticle {
@Override
public void start() {
EventBus eventBus = vertx.eventBus();
eventBus.publish("custom.object.change", "Change 1");
eventBus.publish("custom.object.change", "Change 2");
eventBus.publish("custom.object.change", "Change 3");
}
}
}
```
These examples demonstrate how to implement event-driven architectures using different frameworks in Java. Each framework has its own strengths and use cases, so you can choose the one that best fits your requirements.