Example of emitting on multiple streams

MultipleStreamBolt.java

package storm.examples;

import backtype.storm.task.OutputCollector;
import backtype.storm.task.TopologyContext;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.topology.base.BaseRichBolt;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Tuple;
import backtype.storm.tuple.Values;
import java.util.Map;

public class MultipleStreamBolt extends BaseRichBolt {
    @Override
    public void prepare(Map config, TopologyContext topologyContext, OutputCollector collector) {
        this.collector = collector;
    }

    @Override
    public void execute(Tuple tuple) {
        // Lets break the tuple into pieces
        collector.emit("stream1", tuple, new Values(tuple.getValue(0)));
        collector.emit("stream2", tuple, new Values(tuple.getValue(1)));
        //               ^ stream   ^ anchor   ^ new tuple
        
        // you can still emit on the default stream (e.g. the one named after the bolt)
        collector.emit(tuple, new Values(...));
        
        collector.ack(tuple);
    }

    @Override
    public void declareOutputFields(OutputFieldsDeclarer outputFieldsDeclarer) {
        outputFieldsDeclarer.declareStream("stream1", new Fields("field1"));
        outputFieldsDeclarer.declareStream("stream2", new Fields("field2"));
        outputFieldsDeclarer.declare(new Fields("defaultStreamField")); // if you want
    }
}

This looks very nice.

how know that multiple streams received succesfully.

How do you set the topology for multiple streams?

https://stackoverflow.com/a/30396802/3265888 this post may help on how to setup topology