Strom小实例，大小写转换

package cn.itcast.stormdemo;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Map;
import java.util.UUID;
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.Tuple;
public class SuffixBolt extends BaseBasicBolt{
	
	FileWriter fileWriter = null;
	
	
	//在bolt组件运行过程中只会被调用一次
	@Override
	public void prepare(Map stormConf, TopologyContext context) {
		try {
			fileWriter = new FileWriter("/home/hadoop/stormoutput/"+UUID.randomUUID());
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
		
	}
	
	
	
	//该bolt组件的核心处理逻辑
	//每收到一个tuple消息，就会被调用一次
	@Override
	public void execute(Tuple tuple, BasicOutputCollector collector) {
		//先拿到上一个组件发送过来的商品名称
		String upper_name = tuple.getString(0);
		String suffix_name = upper_name + "_itisok";
		
		
		//为上一个组件发送过来的商品名称添加后缀
		
		try {
			fileWriter.write(suffix_name);
			fileWriter.write("\n");
			fileWriter.flush();
			
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
		
		
		
	}
	
	
	
	//本bolt已经不需要发送tuple消息到下一个组件，所以不需要再声明tuple的字段
	@Override
	public void declareOutputFields(OutputFieldsDeclarer arg0) {
		
	}
}

package cn.itcast.stormdemo;
import backtype.storm.Config;
import backtype.storm.StormSubmitter;
import backtype.storm.generated.AlreadyAliveException;
import backtype.storm.generated.InvalidTopologyException;
import backtype.storm.generated.StormTopology;
import backtype.storm.topology.TopologyBuilder;
/**
 * 组织各个处理组件形成一个完整的处理流程，就是所谓的topology(类似于mapreduce程序中的job)
 * 并且将该topology提交给storm集群去运行，topology提交到集群后就将永无休止地运行，除非人为或者异常退出
 * @author duanhaitao@itcast.cn
 *
 */
public class TopoMain {
	
	public static void main(String[] args) throws Exception {
		
		TopologyBuilder builder = new TopologyBuilder();
		
		//将我们的spout组件设置到topology中去 
		//parallelism_hint ：4  表示用4个excutor来执行这个组件
		//setNumTasks(8) 设置的是该组件执行时的并发task数量，也就意味着1个excutor会运行2个task
		builder.setSpout("randomspout", new RandomWordSpout(), 4).setNumTasks(8);
		
		//将大写转换bolt组件设置到topology，并且指定它接收randomspout组件的消息
		//.shuffleGrouping("randomspout")包含两层含义：
		//1、upperbolt组件接收的tuple消息一定来自于randomspout组件
		//2、randomspout组件和upperbolt组件的大量并发task实例之间收发消息时采用的分组策略是随机分组shuffleGrouping
		builder.setBolt("upperbolt", new UpperBolt(), 4).shuffleGrouping("randomspout");
		
		//将添加后缀的bolt组件设置到topology，并且指定它接收upperbolt组件的消息
		builder.setBolt("suffixbolt", new SuffixBolt(), 4).shuffleGrouping("upperbolt");
		
		//用builder来创建一个topology
		StormTopology demotop = builder.createTopology();
		
		
		//配置一些topology在集群中运行时的参数
		Config conf = new Config();
		//这里设置的是整个demotop所占用的槽位数，也就是worker的数量
		conf.setNumWorkers(4);
		conf.setDebug(true);
		conf.setNumAckers(0);
		
		
		//将这个topology提交给storm集群运行
		StormSubmitter.submitTopology("demotopo", conf, demotop);
		
	}
}

package cn.itcast.stormdemo;
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;
public class UpperBolt extends BaseBasicBolt{
	
	//业务处理逻辑
	@Override
	public void execute(Tuple tuple, BasicOutputCollector collector) {
		
		//先获取到上一个组件传递过来的数据,数据在tuple里面
		String godName = tuple.getString(0);
		
		//将商品名转换成大写
		String godName_upper = godName.toUpperCase();
		
		//将转换完成的商品名发送出去
		collector.emit(new Values(godName_upper));
		
	}
	
	
	//声明该bolt组件要发出去的tuple的字段
	@Override
	public void declareOutputFields(OutputFieldsDeclarer declarer) {
		
		declarer.declare(new Fields("uppername"));
	}
}