CrawlTopology.java

package ${package};

/**
 * Licensed to DigitalPebble Ltd under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * DigitalPebble licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import com.digitalpebble.stormcrawler.*;
import com.digitalpebble.stormcrawler.bolt.FetcherBolt;
import com.digitalpebble.stormcrawler.bolt.JSoupParserBolt;
import com.digitalpebble.stormcrawler.bolt.SiteMapParserBolt;
import com.digitalpebble.stormcrawler.bolt.URLPartitionerBolt;
import com.digitalpebble.stormcrawler.indexing.StdOutIndexer;
import com.digitalpebble.stormcrawler.persistence.StdOutStatusUpdater;
import com.digitalpebble.stormcrawler.spout.MemorySpout;

import org.apache.storm.topology.TopologyBuilder;
import org.apache.storm.tuple.Fields;

/**
 * Dummy topology to play with the spouts and bolts
 */
public class CrawlTopology extends ConfigurableTopology {

    public static void main(String[] args) throws Exception {
        ConfigurableTopology.start(new CrawlTopology(), args);
    }

    @Override
    protected int run(String[] args) {
        TopologyBuilder builder = new TopologyBuilder();

        String[] testURLs = new String[] { "http://www.lequipe.fr/",
                "http://www.lemonde.fr/", "http://www.bbc.co.uk/",
                "http://storm.apache.org/", "http://digitalpebble.com/" };

        builder.setSpout("spout", new MemorySpout(testURLs));

        builder.setBolt("partitioner", new URLPartitionerBolt())
                .shuffleGrouping("spout");

        builder.setBolt("fetch", new FetcherBolt()).fieldsGrouping(
                "partitioner", new Fields("key"));

        builder.setBolt("sitemap", new SiteMapParserBolt())
                .localOrShuffleGrouping("fetch");

        builder.setBolt("parse", new JSoupParserBolt()).localOrShuffleGrouping(
                "sitemap");

        builder.setBolt("index", new StdOutIndexer()).localOrShuffleGrouping(
                "parse");

        Fields furl = new Fields("url");
        
        // can also use MemoryStatusUpdater for simple recursive crawls
        builder.setBolt("status", new StdOutStatusUpdater())
                .fieldsGrouping("fetch", Constants.StatusStreamName, furl)
                .fieldsGrouping("sitemap", Constants.StatusStreamName, furl)
                .fieldsGrouping("parse", Constants.StatusStreamName, furl)
                .fieldsGrouping("index", Constants.StatusStreamName, furl);

        return submit("crawl", conf, builder);
    }
}