【转】storm 开发系列一 第一个程序

原文： http://blog.csdn.net/csfreebird/article/details/49104777

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本文将在本地开发环境创建一个storm程序，力求简单。

首先用mvn创建一个简单的工程hello_storm

mvn archetype:generate -DgroupId=org.csfreebird -DartifactId=hello_storm -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

编辑pom.xml，添加dependency

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.csfreebird</groupId>
  <artifactId>hello_storm</artifactId>
  <version>0.9.5</version>
  <packaging>jar</packaging>
  <name>hello_storm</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>org.apache.storm</groupId>
      <artifactId>storm-core</artifactId>
      <version>${project.version}</version>
      <!-- keep storm out of the jar-with-dependencies -->
      <scope>provided</scope>
    </dependency>
  </dependencies>
</project>

provided 表示storm-core的jar包只作为编译和测试时使用，在集群环境下运行时完全依赖集群环境的storm-core的jar包。

然后重命名App.Java为HelloTopology.java文件，开始编码。模仿之前的Example, 这里将所有的spout/bolt类都作为静态类定义，就放在HelloTopology.java文件。

功能如下

编写HelloTopology.java代码，spout代码来自于TestWordSpout,去掉了log的代码，改变了_引导的成员变量命名方法

package org.csfreebird;

import backtype.storm.Config;
import backtype.storm.LocalCluster;
import backtype.storm.StormSubmitter;
import backtype.storm.task.OutputCollector;
import backtype.storm.task.TopologyContext;
import backtype.storm.testing.TestWordSpout;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.topology.TopologyBuilder;
import backtype.storm.topology.base.BaseRichBolt;
import backtype.storm.topology.base.BaseRichSpout;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Tuple;
import backtype.storm.tuple.Values;
import backtype.storm.utils.Utils;
import backtype.storm.spout.SpoutOutputCollector;
import java.util.Map;
import java.util.TreeMap;
import java.util.Random;

public class HelloTopology {

    public static class HelloSpout extends BaseRichSpout {

    boolean isDistributed;
    SpoutOutputCollector collector;

    public HelloSpout() {
        this(true);
    }

    public HelloSpout(boolean isDistributed) {
        this.isDistributed = isDistributed;
    }

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

    public void close() {
    }

    public void nextTuple() {
        Utils.sleep(100);
        final String[] words = new String[] {"china", "usa", "japan", "russia", "england"};
        final Random rand = new Random();
        final String word = words[rand.nextInt(words.length)];
        this.collector.emit(new Values(word));
    }

    public void ack(Object msgId) {
    }

    public void fail(Object msgId) {
    }

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

    @Override
    public Map<String, Object> getComponentConfiguration() {
        if(!this.isDistributed) {
        Map<String, Object> ret = new TreeMap<String, Object>();
        ret.put(Config.TOPOLOGY_MAX_TASK_PARALLELISM, 1);
        return ret;
        } else {
        return null;
        }
    }
    }

    public static class HelloBolt extends BaseRichBolt {
    OutputCollector collector;

    @Override
    public void prepare(Map conf, TopologyContext context, OutputCollector collector) {
        this.collector = collector;
    }

    @Override
    public void execute(Tuple tuple) {
        this.collector.emit(tuple, new Values("hello," + tuple.getString(0)));
        this.collector.ack(tuple);
    }

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

    public static void main(String[] args) throws Exception {

    TopologyBuilder builder = new TopologyBuilder();
    builder.setSpout("a", new HelloSpout(), 10);
    builder.setBolt("b", new HelloBolt(), 5).shuffleGrouping("a");

    Config conf = new Config();
    conf.setDebug(true);

    if (args != null && args.length > 0) {
        conf.setNumWorkers(3);
        StormSubmitter.submitTopologyWithProgressBar(args[0], conf, builder.createTopology());
    } else {
        String test_id = "hello_test";
        LocalCluster cluster = new LocalCluster();
        cluster.submitTopology(test_id, conf, builder.createTopology());
        Utils.sleep(10000);
        cluster.killTopology(test_id);
        cluster.shutdown();
    }
    }
}

编译成功

mvn clean compile

为了能够在本地模式运行，需要在pom.xml中添加如下：

<build>
  <plugins>
    <plugin>
      <groupId>org.codehaus.mojo</groupId>
      <artifactId>exec-maven-plugin</artifactId>
      <version>1.2.1</version>
      <executions>
        <execution>
          <goals>
            <goal>exec</goal>
          </goals>
        </execution>
      </executions>
      <configuration>
        <executable>java</executable>
        <includeProjectDependencies>true</includeProjectDependencies>
        <includePluginDependencies>false</includePluginDependencies>
        <classpathScope>compile</classpathScope>
        <mainClass>${storm.topology}</mainClass>
      </configuration>
    </plugin>
  </plugins>
</build>

然后运行命令

mvn compile exec:java -Dstorm.topology=org.csfreebird.HelloTopology