/**
* 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 org.apache.nutch.tools;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map.Entry;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.SequenceFileOutputFormat;
import org.apache.hadoop.mapred.TextInputFormat;
import org.apache.hadoop.util.StringUtils;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.nutch.crawl.CrawlDatum;
import org.apache.nutch.crawl.Generator;
import org.apache.nutch.crawl.URLPartitioner;
import org.apache.nutch.net.URLFilters;
import org.apache.nutch.net.URLNormalizers;
import org.apache.nutch.scoring.ScoringFilters;
import org.apache.nutch.util.NutchConfiguration;
import org.apache.nutch.util.NutchJob;
import org.apache.nutch.util.TimingUtil;
/**
* This tool generates fetchlists (segments to be fetched) from plain text
* files containing one URL per line. It's useful when arbitrary URL-s need to
* be fetched without adding them first to the CrawlDb, or during testing.
*/
public class FreeGenerator extends Configured implements Tool {
private static final Logger LOG = LoggerFactory.getLogger(FreeGenerator.class);
private static final String FILTER_KEY = "free.generator.filter";
private static final String NORMALIZE_KEY = "free.generator.normalize";
public static class FG extends MapReduceBase
implements Mapper<WritableComparable<?>, Text, Text, Generator.SelectorEntry>,
Reducer<Text, Generator.SelectorEntry, Text, CrawlDatum> {
private URLNormalizers normalizers = null;
private URLFilters filters = null;
private ScoringFilters scfilters;
private CrawlDatum datum = new CrawlDatum();
private Text url = new Text();
private int defaultInterval = 0;
@Override
public void configure(JobConf job) {
super.configure(job);
defaultInterval = job.getInt("db.fetch.interval.default", 0);
scfilters = new ScoringFilters(job);
if (job.getBoolean(FILTER_KEY, false)) {
filters = new URLFilters(job);
}
if (job.getBoolean(NORMALIZE_KEY, false)) {
normalizers = new URLNormalizers(job, URLNormalizers.SCOPE_INJECT);
}
}
Generator.SelectorEntry entry = new Generator.SelectorEntry();
public void map(WritableComparable<?> key, Text value, OutputCollector<Text,
Generator.SelectorEntry> output, Reporter reporter) throws IOException {
// value is a line of text
String urlString = value.toString();
try {
if (normalizers != null) {
urlString = normalizers.normalize(urlString, URLNormalizers.SCOPE_INJECT);
}
if (urlString != null && filters != null) {
urlString = filters.filter(urlString);
}
if (urlString != null) {
url.set(urlString);
scfilters.injectedScore(url, datum);
}
} catch (Exception e) {
LOG.warn("Error adding url '" + value.toString() + "', skipping: " + StringUtils.stringifyException(e));
return;
}
if (urlString == null) {
if (LOG.isDebugEnabled()) {
LOG.debug("- skipping " + value.toString());
}
return;
}
entry.datum = datum;
entry.url = url;
// https://issues.apache.org/jira/browse/NUTCH-1430
entry.datum.setFetchInterval(defaultInterval);
output.collect(url, entry);
}
public void reduce(Text key, Iterator<Generator.SelectorEntry> values,
OutputCollector<Text, CrawlDatum> output, Reporter reporter) throws IOException {
// pick unique urls from values - discard the reduce key due to hash collisions
HashMap<Text, CrawlDatum> unique = new HashMap<Text, CrawlDatum>();
while (values.hasNext()) {
Generator.SelectorEntry entry = values.next();
unique.put(entry.url, entry.datum);
}
// output unique urls
for (Entry<Text, CrawlDatum> e : unique.entrySet()) {
output.collect(e.getKey(), e.getValue());
}
}
}
public int run(String[] args) throws Exception {
if (args.length < 2) {
System.err.println("Usage: FreeGenerator <inputDir> <segmentsDir> [-filter] [-normalize]");
System.err.println("\tinputDir\tinput directory containing one or more input files.");
System.err.println("\t\tEach text file contains a list of URLs, one URL per line");
System.err.println("\tsegmentsDir\toutput directory, where new segment will be created");
System.err.println("\t-filter\trun current URLFilters on input URLs");
System.err.println("\t-normalize\trun current URLNormalizers on input URLs");
return -1;
}
boolean filter = false;
boolean normalize = false;
if (args.length > 2) {
for (int i = 2; i < args.length; i++) {
if (args[i].equals("-filter")) {
filter = true;
} else if (args[i].equals("-normalize")) {
normalize = true;
} else {
LOG.error("Unknown argument: " + args[i] + ", exiting ...");
return -1;
}
}
}
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
long start = System.currentTimeMillis();
LOG.info("FreeGenerator: starting at " + sdf.format(start));
JobConf job = new NutchJob(getConf());
job.setBoolean(FILTER_KEY, filter);
job.setBoolean(NORMALIZE_KEY, normalize);
FileInputFormat.addInputPath(job, new Path(args[0]));
job.setInputFormat(TextInputFormat.class);
job.setMapperClass(FG.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(Generator.SelectorEntry.class);
job.setPartitionerClass(URLPartitioner.class);
job.setReducerClass(FG.class);
String segName = Generator.generateSegmentName();
job.setNumReduceTasks(job.getNumMapTasks());
job.setOutputFormat(SequenceFileOutputFormat.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(CrawlDatum.class);
job.setOutputKeyComparatorClass(Generator.HashComparator.class);
FileOutputFormat.setOutputPath(job, new Path(args[1],
new Path(segName, CrawlDatum.GENERATE_DIR_NAME)));
try {
JobClient.runJob(job);
} catch (Exception e) {
LOG.error("FAILED: " + StringUtils.stringifyException(e));
return -1;
}
long end = System.currentTimeMillis();
LOG.info("FreeGenerator: finished at " + sdf.format(end) + ", elapsed: " + TimingUtil.elapsedTime(start, end));
return 0;
}
public static void main(String[] args) throws Exception {
int res = ToolRunner.run(NutchConfiguration.create(), new FreeGenerator(), args);
System.exit(res);
}
}