（二） kafka-jstorm集群实时日志分析 之 ---------jstorm集成spring

    　后面为了引入Dubbo RPC框架（用spring配置），先把spring 引入jstorm中，请先了解一下jsorm多线程方面的文档：http://storm.apache.org/documentation/Understanding-the-parallelism-of-a-Storm-topology.html　．

　　

A worker process executes a subset of a topology. A worker process belongs to a specific topology and may run one or more executors for one or more components (spouts or bolts) of this topology. A running topology consists of many such processes running on many machines within a Storm cluster.

An executor is a thread that is spawned by a worker process. It may run one or more tasks for the same component (spout or bolt).

A task performs the actual data processing — each spout or bolt that you implement in your code executes as many tasks across the cluster. The number of tasks for a component is always the same throughout the lifetime of a topology, but the number of executors (threads) for a component can change over time. This means that the following condition holds true: #threads ≤ #tasks. By default, the number of tasks is set to be the same as the number of executors, i.e. Storm will run one task per thread.

　　不管是spout还是bolt，都会被每个线程初始化，（你可以打印日志，或断点观察）．Bolt的prepare方法，或Spout方法的open方法都会随着实例化而调用，你可以认为是特殊的构造函数吧．

　　多线程环境下每个ｂｏｌｔ的每个实例都可能被不同机器执行．每个ｂｏｌｔ所需要的服务可能不同，这就需要在每个Bolt类中加载ｓｐｒｉｎｇ，即初始化．比如

<span style="font-size:18px;">public static class WordCounterBoltCh03 extends BaseRichBolt {
		private static final Logger log = LoggerFactory.getLogger(WordCounterBoltCh03.class);

		private static final long serialVersionUID = 1L;
		private Map<String, Integer> countMap;
		private OutputCollector collector;
		private String name;
		private int id;
		
		private static final ApplicationContext applicationContext;
		private static final LogManager logManager;
		
		static{
			applicationContext = SpringUtil.of("learningJstormConfig/spring-kafkabolt-context.xml");／／ｓｐｒｉｎｇ初始化
			logManager = applicationContext.getBean(LogManager.class);
			log.info("--------------ApplicationContext initialized from learningJstormConfig/spring-kafkabolt-context.xml ");
		}

		@Override
		public void prepare(Map stormConf, TopologyContext context, OutputCollector collector) {
			this.countMap = new HashMap<>();
			this.collector = collector;
			this.name = context.getThisComponentId();
			this.id = context.getThisTaskId();
			log.info("-----------------WordCounterBoltCh03 prepare");
		}

		@Override
		public void execute(Tuple input) {
			String word = null;
			try {
				word = input.getStringByField("word");
			} catch (Throwable e) {
			}
			if (null != word) {
				if (!countMap.containsKey(word)) {
					countMap.put(word, 1);
				} else {
					Integer count = countMap.get(word);
					count++;
					countMap.put(word, count);
					
					logManager.write(word + ":" + countMap.get(word));
				}
			} else {
				if ("signals.".equals(input.getSourceStreamId()) && "refreshCache".equals(input.getStringByField("action"))) {
					cleanup();
					countMap.clear();
				}
			}

			this.collector.ack(input);

		}

		@Override
		public void declareOutputFields(OutputFieldsDeclarer declarer) {

		}

		@Override
		public void cleanup() {
			log.info("{cleanup................}");
			countMap.forEach((k, v) -> {
				log.info("{clean up.................}");
				log.info("k : {} , v : {}", k, v);
			});
		}

	}</span>

　spring配置文件如下：

<span style="font-size:18px;"><?xml version="1.0" encoding="UTF-8"?>
<beans 
    xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
	xmlns:task="http://www.springframework.org/schema/task"
	xsi:schemaLocation="
		http://www.springframework.org/schema/beans
		http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://code.alibabatech.com/schema/dubbo
		http://code.alibabatech.com/schema/dubbo/dubbo.xsd 
		http://www.springframework.org/schema/task
        http://www.springframework.org/schema/task/spring-task.xsd">
        
  <import resource="classpath:/learningJstormConfig/dubbo-provider.xml"/>     
  <context:component-scan base-package="com.doctor.kafkajstrom.log.manager.imp" />
  <context:component-scan base-package="com.doctor.kafkajstrom.log.service.imp" />
  <context:component-scan base-package="com.doctor.kafkajstrom.component" />
</beans></span>

　最好，每个Spout,每个Bolt都定制Spring配置文件．即每个Spout,每个Bolt都加载并初始化Spring环境．