Storm例子

例子说明：先随机产生一个数，然后乘以16，再然后添加一串字符串并转大写，再然后存入文件中

Main:

public class Main {
	public static void main(String[] args) throws InterruptedException, AlreadyAliveException, InvalidTopologyException {
		TopologyBuilder builder = new TopologyBuilder();
		builder.setSpout("randomint", new RandomSpout(), 1);
		builder.setBolt("multiply", new MultiplyBolt(), 3).shuffleGrouping("randomint");
		builder.setBolt("add", new AddBolt(), 3).shuffleGrouping("multiply");
		builder.setBolt("end", new EndBolt(), 3).shuffleGrouping("add");
		
		Config config = new Config();
		config.setDebug(true);
		if(args !=null && args.length > 0){
			config.setNumWorkers(3);
			StormSubmitter.submitTopology("goto", config, builder.createTopology());
		} else {			
			config.setMaxTaskParallelism(1);
			LocalCluster cluster = new LocalCluster();
			cluster.submitTopology("go", config, builder.createTopology());
			Thread.sleep(10000);
			cluster.shutdown();
		}
	}
}

randomint :

public class RandomSpout extends BaseRichSpout {
	private static final long serialVersionUID = 1L;
	private SpoutOutputCollector collator;
	@SuppressWarnings("rawtypes")
	public void open(Map conf, TopologyContext context, SpoutOutputCollector collector) {
		this.collator = collector;
	}

	public void nextTuple() {
		int num = getRandomInt();
		collator.emit(new Values(num));
	}

	public void declareOutputFields(OutputFieldsDeclarer declarer) {
		declarer.declare(new Fields("randomint"));
	}
	private int getRandomInt(){
		return new Random().nextInt(10000);
	}
}

multiply :

public class MultiplyBolt extends BaseBasicBolt {
	private static final long serialVersionUID = -2510535748201371391L;

	public void execute(Tuple input, BasicOutputCollector collector) {
		Integer num = input.getInteger(0);
		if(num==null){
			num = 0;
		}
		num = num * 16;
		collector.emit(new Values(num));
	}

	public void declareOutputFields(OutputFieldsDeclarer declarer) {
		declarer.declare(new Fields("multiply"));
	}

}

add :

public class AddBolt extends BaseBasicBolt {
	private static final long serialVersionUID = 7852933092789941359L;

	public void execute(Tuple input, BasicOutputCollector collector) {
		Integer num = input.getInteger(0);
		String s = "is num : " + num;
		s = s.toUpperCase();
		collector.emit(new Values(s));
	}

	public void declareOutputFields(OutputFieldsDeclarer declarer) {
		declarer.declare(new Fields("add"));
	}

}

end :

public class EndBolt extends BaseBasicBolt {
	private static final long serialVersionUID = -7167182237528493192L;

	public void execute(Tuple input, BasicOutputCollector collector) {
		String msg = input.getString(0);
		FileUtil.writer(msg);
		try {
			Thread.sleep(2000);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}

	public void declareOutputFields(OutputFieldsDeclarer declarer) {
		declarer.declare(new Fields("end"));
	}

}

FileUtil :

public class FileUtil {
	public static void writer(String msg){
		FileWriter writer = null;
		try {
			writer = new FileWriter("/tool/out.txt", true);
			writer.append(msg+"\n");
			writer.flush();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				if(writer!=null){
					writer.close();
					writer = null;
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
}