CallbackHellSetter.java

package com.example.tryRxVertx;

import io.vertx.core.AbstractVerticle;
import io.vertx.core.shareddata.AsyncMap;

public class CallbackHellSetter extends AbstractVerticle {
    @Override
    public void start() throws Exception {
        vertx.setPeriodic(300, event -> {
            vertx.sharedData().<String,Long>getClusterWideMap("mymap", resOfGetMap -> {
                if(resOfGetMap.succeeded()){
                    AsyncMap<String,Long> clusterMap = resOfGetMap.result();
                    Long newValue = System.currentTimeMillis();
                    clusterMap.put("timestamp", newValue, resOfPut -> {
                        if(resOfPut.succeeded()){
                            System.out.println("successfully updated value");
                        } else resOfPut.cause().printStackTrace();
                    });
                } else resOfGetMap.cause().printStackTrace();
            });
        });
    }
}