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This article introduces the relevant knowledge of "how to use Storm RandomURLSpout". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Background: you need to have a detailed understanding of the basic processing mechanisms of Storm.

Package com.digitalpebble.storm.crawler.spout;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 RandomURLSpout extends BaseRichSpout {SpoutOutputCollector _ collector; Random _ rand Public void open (Map conf, TopologyContext context, SpoutOutputCollector collector) {_ collector = collector; _ rand = new Random ();} public void nextTuple () {Utils.sleep String [] urls = new String [] {"http://www.lequipe.fr/"," http://www.lemonde.fr/", "http://www.bbc.co.uk/"," http://www.facebook.com/", "http://www.rmc.fr"} String url = urls [_ rand.nextInt (urls.length)]; _ collector.emit (new Values (url));} @ Override public void ack (Object id) {} @ Override public void fail (Object id) {} public void declareOutputFields (OutputFieldsDeclarer declarer) {declarer.declare (new Fields ("url")) }}

Here, we inherit

BaseRichSpout

SimpleTips, where URL objects will continue to emit the URL objects we need.

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