Java tutorial
/* * 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.mahout.text.wikipedia; import java.io.File; import java.io.IOException; import java.util.Locale; import java.util.Set; import com.google.common.collect.Sets; import org.apache.commons.cli2.CommandLine; import org.apache.commons.cli2.Group; import org.apache.commons.cli2.Option; import org.apache.commons.cli2.OptionException; import org.apache.commons.cli2.builder.ArgumentBuilder; import org.apache.commons.cli2.builder.DefaultOptionBuilder; import org.apache.commons.cli2.builder.GroupBuilder; import org.apache.commons.cli2.commandline.Parser; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.DefaultStringifier; import org.apache.hadoop.io.Stringifier; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Job; import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat; import org.apache.hadoop.util.GenericsUtil; import org.apache.lucene.analysis.Analyzer; import org.apache.mahout.common.ClassUtils; import org.apache.mahout.common.CommandLineUtil; import org.apache.mahout.common.HadoopUtil; import org.apache.mahout.common.commandline.DefaultOptionCreator; import org.apache.mahout.common.iterator.FileLineIterable; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Create and run the Wikipedia Dataset Creator. */ public final class WikipediaDatasetCreatorDriver { private static final Logger log = LoggerFactory.getLogger(WikipediaDatasetCreatorDriver.class); private WikipediaDatasetCreatorDriver() { } /** * Takes in two arguments: * <ol> * <li>The input {@link org.apache.hadoop.fs.Path} where the input documents live</li> * <li>The output {@link org.apache.hadoop.fs.Path} where to write the classifier as a * {@link org.apache.hadoop.io.SequenceFile}</li> * </ol> */ public static void main(String[] args) throws IOException, InterruptedException { DefaultOptionBuilder obuilder = new DefaultOptionBuilder(); ArgumentBuilder abuilder = new ArgumentBuilder(); GroupBuilder gbuilder = new GroupBuilder(); Option dirInputPathOpt = DefaultOptionCreator.inputOption().create(); Option dirOutputPathOpt = DefaultOptionCreator.outputOption().create(); Option categoriesOpt = obuilder.withLongName("categories").withRequired(true) .withArgument(abuilder.withName("categories").withMinimum(1).withMaximum(1).create()) .withDescription("Location of the categories file. One entry per line. " + "Will be used to make a string match in Wikipedia Category field") .withShortName("c").create(); Option exactMatchOpt = obuilder.withLongName("exactMatch") .withDescription("If set, then the category name must exactly match the " + "entry in the categories file. Default is false") .withShortName("e").create(); Option analyzerOpt = obuilder.withLongName("analyzer").withRequired(false) .withArgument(abuilder.withName("analyzer").withMinimum(1).withMaximum(1).create()) .withDescription("The analyzer to use, must have a no argument constructor").withShortName("a") .create(); Option helpOpt = DefaultOptionCreator.helpOption(); Group group = gbuilder.withName("Options").withOption(categoriesOpt).withOption(dirInputPathOpt) .withOption(dirOutputPathOpt).withOption(exactMatchOpt).withOption(analyzerOpt).withOption(helpOpt) .create(); Parser parser = new Parser(); parser.setGroup(group); try { CommandLine cmdLine = parser.parse(args); if (cmdLine.hasOption(helpOpt)) { CommandLineUtil.printHelp(group); return; } String inputPath = (String) cmdLine.getValue(dirInputPathOpt); String outputPath = (String) cmdLine.getValue(dirOutputPathOpt); String catFile = (String) cmdLine.getValue(categoriesOpt); Class<? extends Analyzer> analyzerClass = WikipediaAnalyzer.class; if (cmdLine.hasOption(analyzerOpt)) { String className = cmdLine.getValue(analyzerOpt).toString(); analyzerClass = Class.forName(className).asSubclass(Analyzer.class); // try instantiating it, b/c there isn't any point in setting it if // you can't instantiate it ClassUtils.instantiateAs(analyzerClass, Analyzer.class); } runJob(inputPath, outputPath, catFile, cmdLine.hasOption(exactMatchOpt), analyzerClass); } catch (OptionException e) { log.error("Exception", e); CommandLineUtil.printHelp(group); } catch (ClassNotFoundException e) { log.error("Exception", e); CommandLineUtil.printHelp(group); } } /** * Run the job * * @param input * the input pathname String * @param output * the output pathname String * @param catFile * the file containing the Wikipedia categories * @param exactMatchOnly * if true, then the Wikipedia category must match exactly instead of simply containing the * category string */ public static void runJob(String input, String output, String catFile, boolean exactMatchOnly, Class<? extends Analyzer> analyzerClass) throws IOException, InterruptedException, ClassNotFoundException { Configuration conf = new Configuration(); conf.set("key.value.separator.in.input.line", " "); conf.set("xmlinput.start", "<page>"); conf.set("xmlinput.end", "</page>"); conf.setBoolean("exact.match.only", exactMatchOnly); conf.set("analyzer.class", analyzerClass.getName()); conf.set("io.serializations", "org.apache.hadoop.io.serializer.JavaSerialization," + "org.apache.hadoop.io.serializer.WritableSerialization"); // Dont ever forget this. People should keep track of how hadoop conf // parameters can make or break a piece of code Set<String> categories = Sets.newHashSet(); for (String line : new FileLineIterable(new File(catFile))) { categories.add(line.trim().toLowerCase(Locale.ENGLISH)); } Stringifier<Set<String>> setStringifier = new DefaultStringifier<Set<String>>(conf, GenericsUtil.getClass(categories)); String categoriesStr = setStringifier.toString(categories); conf.set("wikipedia.categories", categoriesStr); Job job = new Job(conf); log.info("Input: {} Out: {} Categories: {}", input, output, catFile); job.setJarByClass(WikipediaDatasetCreatorDriver.class); job.setOutputKeyClass(Text.class); job.setOutputValueClass(Text.class); job.setMapperClass(WikipediaDatasetCreatorMapper.class); //TODO: job.setNumMapTasks(100); job.setInputFormatClass(XmlInputFormat.class); job.setReducerClass(WikipediaDatasetCreatorReducer.class); job.setOutputFormatClass(TextOutputFormat.class); FileInputFormat.setInputPaths(job, new Path(input)); Path outPath = new Path(output); FileOutputFormat.setOutputPath(job, outPath); HadoopUtil.delete(conf, outPath); boolean succeeded = job.waitForCompletion(true); if (!succeeded) { throw new IllegalStateException("Job failed!"); } } }