Registering a Listener

To register a listener, you must implement an interface called org.springframework.cloud.zookeeper.discovery.watcher.DependencyWatcherListener and register it as a bean. The interface gives you one method:

void stateChanged(String dependencyName, DependencyState newState);

If you want to register a listener for a particular dependency, the dependencyName would be the discriminator for your concrete implementation. newState provides you with information about whether your dependency has changed to CONNECTED or DISCONNECTED.