MultipleCrawlerController.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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.
 */

package edu.uci.ics.crawler4j.examples.multiple;

import edu.uci.ics.crawler4j.crawler.CrawlConfig;
import edu.uci.ics.crawler4j.crawler.CrawlController;
import edu.uci.ics.crawler4j.fetcher.PageFetcher;
import edu.uci.ics.crawler4j.robotstxt.RobotstxtConfig;
import edu.uci.ics.crawler4j.robotstxt.RobotstxtServer;

/**
 * @author Yasser Ganjisaffar <lastname at gmail dot com>
 */

public class MultipleCrawlerController {

	public static void main(String[] args) throws Exception {
		if (args.length != 1) {
			System.out.println("Needed parameter: ");
			System.out.println("\t rootFolder (it will contain intermediate crawl data)");
			return;
		}

		/*
		 * crawlStorageFolder is a folder where intermediate crawl data is
		 * stored.
		 */
		String crawlStorageFolder = args[0];

		CrawlConfig config1 = new CrawlConfig();
		CrawlConfig config2 = new CrawlConfig();

		/*
		 * The two crawlers should have different storage folders for their
		 * intermediate data
		 */
		config1.setCrawlStorageFolder(crawlStorageFolder + "/crawler1");
		config2.setCrawlStorageFolder(crawlStorageFolder + "/crawler2");

		config1.setPolitenessDelay(1000);
		config2.setPolitenessDelay(2000);

		config1.setMaxPagesToFetch(50);
		config2.setMaxPagesToFetch(100);

		/*
		 * We will use different PageFetchers for the two crawlers.
		 */
		PageFetcher pageFetcher1 = new PageFetcher(config1);
		PageFetcher pageFetcher2 = new PageFetcher(config2);

		/*
		 * We will use the same RobotstxtServer for both of the crawlers.
		 */
		RobotstxtConfig robotstxtConfig = new RobotstxtConfig();
		RobotstxtServer robotstxtServer = new RobotstxtServer(robotstxtConfig, pageFetcher1);

		CrawlController controller1 = new CrawlController(config1, pageFetcher1, robotstxtServer);
		CrawlController controller2 = new CrawlController(config2, pageFetcher2, robotstxtServer);

		String[] crawler1Domains = new String[] { "http://www.ics.uci.edu/", "http://www.cnn.com/" };
		String[] crawler2Domains = new String[] { "http://en.wikipedia.org/" };

		controller1.setCustomData(crawler1Domains);
		controller2.setCustomData(crawler2Domains);

		controller1.addSeed("http://www.ics.uci.edu/");
		controller1.addSeed("http://www.cnn.com/");
		controller1.addSeed("http://www.ics.uci.edu/~lopes/");
		controller1.addSeed("http://www.cnn.com/POLITICS/");

		controller2.addSeed("http://en.wikipedia.org/wiki/Main_Page");
		controller2.addSeed("http://en.wikipedia.org/wiki/Obama");
		controller2.addSeed("http://en.wikipedia.org/wiki/Bing");

		/*
		 * The first crawler will have 5 cuncurrent threads and the second
		 * crawler will have 7 threads.
		 */
		controller1.startNonBlocking(BasicCrawler.class, 5);
		controller2.startNonBlocking(BasicCrawler.class, 7);

		controller1.waitUntilFinish();
		System.out.println("Crawler 1 is finished.");

		controller2.waitUntilFinish();
		System.out.println("Crawler 2 is finished.");
	}
}