Documentation Version: 3.6-EA2 - Publication Date : Nov 25, 2015

Listening for Distributed Object Events

The Distributed Object Listener methods distributedObjectCreated and distributedObjectDestroyed are invoked when a distributed object is created and destroyed throughout the cluster. To write a Distributed Object Listener class, you implement the DistributedObjectListener interface and its methods.

The following is an example Distributed Object Listener class.

public class Sample implements DistributedObjectListener {
  public static void main(String[] args) {
    Sample sample = new Sample();

    Config config = new Config();
    HazelcastInstance hazelcastInstance = Hazelcast.newHazelcastInstance(config);
    hazelcastInstance.addDistributedObjectListener(sample);

    Collection<DistributedObject> distributedObjects = hazelcastInstance.getDistributedObjects();
    for (DistributedObject distributedObject : distributedObjects) {
      System.out.println(distributedObject.getName() + "," + distributedObject.getId());
    }
  }

  @Override
  public void distributedObjectCreated(DistributedObjectEvent event) {
    DistributedObject instance = event.getDistributedObject();
    System.out.println("Created " + instance.getName() + "," + instance.getId());
  }

  @Override
  public void distributedObjectDestroyed(DistributedObjectEvent event) {
    DistributedObject instance = event.getDistributedObject();
    System.out.println("Destroyed " + instance.getName() + "," + instance.getId());
  }
}

When a respective event is fired, the distributed object listener outputs the event type, and the name, service (for example, if a Map service provides the distributed object, than it is a Map object), and ID of the object.