学步园

storm的程序开发可以理解为三步骤

（1）Spout

（2）blot

（3）main类（这个应该一成不变）

废话不多讲，直接上代码：

package	main.java.storm.cookbook;
import java.util.Map;
import java.util.Random;


import backtype.storm.spout.SpoutOutputCollector;
import backtype.storm.task.TopologyContext;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.topology.base.BaseRichSpout;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Values;
import backtype.storm.utils.Utils;

public class HelloWorldSpout extends BaseRichSpout {
	
	private static final long serialVersionUID = -4646687160233411001L;

	private SpoutOutputCollector collector;
	
	private int referenceRandom;
	
	private static final int MAX_RANDOM = 10;
	
	public HelloWorldSpout(){
		final Random rand = new Random();
		referenceRandom = rand.nextInt(MAX_RANDOM);
	}

	@Override
	public void open(Map conf, TopologyContext context,
			SpoutOutputCollector collector) {
		this.collector = collector;

	}

	@Override
	public void nextTuple() {
		Utils.sleep(100);
		final Random rand = new Random();
		int instanceRandom = rand.nextInt(MAX_RANDOM);
		if(instanceRandom == referenceRandom){
			collector.emit(new Values("Hello World"));
		} else {
			collector.emit(new Values("Other Random Word"));
		}
		

	}

	@Override
	public void declareOutputFields(OutputFieldsDeclarer declarer) {
		declarer.declare(new Fields("sentence"));
	}

}

blot代码：

package	main.java.storm.cookbook;

import java.util.Map;

import org.apache.log4j.Logger;

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;

public class HelloWorldBolt extends BaseRichBolt {
	
	public static Logger LOG = Logger.getLogger(HelloWorldBolt.class);
	
	private static final long serialVersionUID = -841805977046116528L;
	
	private int myCount = 0;

	@Override
	public void prepare(Map stormConf, TopologyContext context,
			OutputCollector collector) {
	}

	@Override
	public void execute(Tuple input) {
		String test = input.getStringByField("sentence");
		if(test == "Hello World"){
			myCount++;
			System.out.println("Found a Hello World! My Count is now: " + Integer.toString(myCount));
			LOG.debug("Found a Hello World! My Count is now: " + Integer.toString(myCount));
		}
	}

	@Override
	public void declareOutputFields(OutputFieldsDeclarer declarer) {
		declarer.declare(new Fields("myCount"));

	}

}

主类开发：

package	main.java.storm.cookbook;

import backtype.storm.Config;
import backtype.storm.LocalCluster;
import backtype.storm.StormSubmitter;
import backtype.storm.topology.TopologyBuilder;
import backtype.storm.utils.Utils;

public class HelloWorldTopology {

	/**
	 * @param args
	 * @throws Exception 
	 * @throws  
	 */
	public static void main(String[] args) throws Exception {
		TopologyBuilder builder = new TopologyBuilder();
        
        builder.setSpout("randomHelloWorld", new HelloWorldSpout(), 2);        
        builder.setBolt("HelloWorldBolt", new HelloWorldBolt(), 10)
                .<u><span style="color:#ff0000;">shuffleGrouping("randomHelloWorld"); //设置依赖，说明接受哪边来的数据</span></u>
                
        Config conf = new Config();
        conf.setDebug(true);
        
        if(args!=null && args.length > 0) {
            conf.setNumWorkers(20);
            
            StormSubmitter.submitTopology(args[0], conf, builder.createTopology());
        } else {
        
            LocalCluster cluster = new LocalCluster();
            cluster.submitTopology("test", conf, builder.createTopology());
            Utils.sleep(10000);
            cluster.killTopology("test");
            cluster.shutdown();    
        }

	}

}