package storm.starter;
import backtype.storm.Config;
import backtype.storm.LocalCluster;
import backtype.storm.LocalDRPC;
import backtype.storm.StormSubmitter;
import backtype.storm.drpc.LinearDRPCTopologyBuilder;
import backtype.storm.task.TopologyContext;
import backtype.storm.topology.BasicOutputCollector;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.topology.base.BaseBasicBolt;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Tuple;
import backtype.storm.tuple.Values;
import java.util.Map;
/**
* This topology is a basic example of doing distributed RPC on top of Storm. It implements a function
* that appends a "!" to any string you send the DRPC function.
*
* See https://github.com/nathanmarz/storm/wiki/Distributed-RPC for more information on
* doing distributed RPC on top of Storm.
*/
public class BasicDRPCTopology {
public static class ExclaimBolt extends BaseBasicBolt {
@Override
public void execute(Tuple tuple, BasicOutputCollector collector) {
String input = tuple.getString(1);
collector.emit(new Values(tuple.getValue(0), input + "!"));
}
@Override
public void declareOutputFields(OutputFieldsDeclarer declarer) {
declarer.declare(new Fields("id", "result"));
}
}
public static void main(String[] args) throws Exception {
LinearDRPCTopologyBuilder builder = new LinearDRPCTopologyBuilder("exclamation");
builder.addBolt(new ExclaimBolt(), 3);
Config conf = new Config();
if(args==null || args.length==0) {
LocalDRPC drpc = new LocalDRPC();
LocalCluster cluster = new LocalCluster();
cluster.submitTopology("drpc-demo", conf, builder.createLocalTopology(drpc));
for(String word: new String[] {"hello", "goodbye"}) {
System.out.println("Result for \"" + word + "\": "
+ drpc.execute("exclamation", word));
}
cluster.shutdown();
drpc.shutdown();
} else {
conf.setNumWorkers(3);
StormSubmitter.submitTopology(args[0], conf, builder.createRemoteTopology());
}
}
}