Java tutorial
/* * ClueWeb Tools: Hadoop tools for manipulating ClueWeb collections * * Licensed 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 io.bfscan.clueweb12; import io.bfscan.data.VByteDocVector; import io.bfscan.dictionary.DefaultFrequencySortedDictionary; import java.io.IOException; import java.util.Arrays; import java.util.List; import org.apache.commons.cli.CommandLine; import org.apache.commons.cli.CommandLineParser; import org.apache.commons.cli.GnuParser; import org.apache.commons.cli.HelpFormatter; import org.apache.commons.cli.OptionBuilder; import org.apache.commons.cli.Options; import org.apache.commons.cli.ParseException; import org.apache.hadoop.conf.Configured; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.BytesWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Job; import org.apache.hadoop.mapreduce.Mapper; import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat; import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat; import org.apache.hadoop.util.Tool; import org.apache.hadoop.util.ToolRunner; import org.apache.log4j.Logger; import com.google.common.base.Joiner; import com.google.common.collect.Lists; public class ProcessVByteDocVectors extends Configured implements Tool { private static final Logger LOG = Logger.getLogger(ProcessVByteDocVectors.class); private static final Joiner JOINER = Joiner.on("|"); private static class MyMapper extends Mapper<Text, BytesWritable, Text, Text> { private static final VByteDocVector DOC = new VByteDocVector(); private DefaultFrequencySortedDictionary dictionary; @Override public void setup(Context context) throws IOException { FileSystem fs = FileSystem.get(context.getConfiguration()); String path = context.getConfiguration().get(DICTIONARY_OPTION); dictionary = new DefaultFrequencySortedDictionary(path, fs); } @Override public void map(Text key, BytesWritable bytes, Context context) throws IOException, InterruptedException { VByteDocVector.fromBytesWritable(bytes, DOC); List<String> terms = Lists.newArrayList(); for (int termid : DOC.getTermIds()) { terms.add(dictionary.getTerm(termid)); } context.write(key, new Text(JOINER.join(terms))); } } public static final String INPUT_OPTION = "input"; public static final String OUTPUT_OPTION = "output"; public static final String DICTIONARY_OPTION = "dictionary"; /** * Runs this tool. */ @SuppressWarnings("static-access") public int run(String[] args) throws Exception { Options options = new Options(); options.addOption( OptionBuilder.withArgName("path").hasArg().withDescription("input path").create(INPUT_OPTION)); options.addOption( OptionBuilder.withArgName("path").hasArg().withDescription("output path").create(OUTPUT_OPTION)); options.addOption( OptionBuilder.withArgName("path").hasArg().withDescription("dictionary").create(DICTIONARY_OPTION)); CommandLine cmdline; CommandLineParser parser = new GnuParser(); try { cmdline = parser.parse(options, args); } catch (ParseException exp) { HelpFormatter formatter = new HelpFormatter(); formatter.printHelp(this.getClass().getName(), options); ToolRunner.printGenericCommandUsage(System.out); System.err.println("Error parsing command line: " + exp.getMessage()); return -1; } if (!cmdline.hasOption(INPUT_OPTION) || !cmdline.hasOption(OUTPUT_OPTION) || !cmdline.hasOption(DICTIONARY_OPTION)) { HelpFormatter formatter = new HelpFormatter(); formatter.printHelp(this.getClass().getName(), options); ToolRunner.printGenericCommandUsage(System.out); return -1; } String input = cmdline.getOptionValue(INPUT_OPTION); String output = cmdline.getOptionValue(OUTPUT_OPTION); String dictionary = cmdline.getOptionValue(DICTIONARY_OPTION); LOG.info("Tool name: " + ProcessVByteDocVectors.class.getSimpleName()); LOG.info(" - input: " + input); LOG.info(" - output: " + output); LOG.info(" - dictionary: " + dictionary); Job job = new Job(getConf(), ProcessVByteDocVectors.class.getSimpleName() + ":" + input); job.setJarByClass(ProcessVByteDocVectors.class); job.setNumReduceTasks(0); FileInputFormat.setInputPaths(job, input); FileOutputFormat.setOutputPath(job, new Path(output)); job.getConfiguration().set(DICTIONARY_OPTION, dictionary); job.setInputFormatClass(SequenceFileInputFormat.class); job.setOutputFormatClass(TextOutputFormat.class); job.setMapOutputKeyClass(Text.class); job.setMapOutputValueClass(Text.class); job.setMapperClass(MyMapper.class); FileSystem.get(getConf()).delete(new Path(output), true); long startTime = System.currentTimeMillis(); job.waitForCompletion(true); LOG.info("Job Finished in " + (System.currentTimeMillis() - startTime) / 1000.0 + " seconds"); return 0; } /** * Dispatches command-line arguments to the tool via the <code>ToolRunner</code>. */ public static void main(String[] args) throws Exception { LOG.info("Running " + ProcessVByteDocVectors.class.getCanonicalName() + " with args " + Arrays.toString(args)); ToolRunner.run(new ProcessVByteDocVectors(), args); } }