storm学习四 开发简单的Topology程序

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：

packagemain.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：

packagemain.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：

packagemain.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();    
        }

}

}