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tf-idf hadoop map reduce
package com.jumei.robot.mapreduce.tfidf;import java.io.IOException;import java.util.Collection;import java.util.Comparator;import java.util.Map.Entry;import java.util.Set;import java.util.StringTokenizer;import java.util.TreeMap;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.fs.FileSystem;import org.apache.hadoop.fs.Path;import org.apache.hadoop.io.LongWritable;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.input.FileSplit;import org.apache.hadoop.mapreduce.lib.input.KeyValueTextInputFormat;import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;import org.apache.hadoop.mapreduce.lib.output.MultipleOutputs;import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import com.jumei.robot.common.beans.Word;import com.jumei.robot.preprocess.IFilterStopwordService;import com.jumei.robot.preprocess.IWordSegService;/** * <pre> * TF-IDF 算法MapReduce实现 * 分3job * job 1: 统计文档中单词在该文档中出现的次数(n)及该文档所有单词的总数(N) * job 2: 统计单词所包含的文档数(d),根据所有文档的总数(D),计算tf-idf值 * job 3: 对job2进行排序,输出tf-idf值最大的前top N个词 * 数学公式: * tf = n / N * idf = Math.log(D / d); * tf-idf = tf * idf * </pre> * @author deyin * */public class TfIdfMapReduce { private static Configuration conf; public static void main(String[] args) throws Exception { conf = new Configuration(); if (args.length < 3) { System.err.println("arguments invalid, usgae: hadoop jar tfidf.jar com.jumei.robot.mapreduce.tfidf.TfIdfMapReduce <hdfs input folder> <hdfs output folder> <number of documents> <topN>"); return; } String pathin = args[0]; String pathout = args[1]; int nrOfDocuments = Integer.parseInt(args[2]); int topN = Integer.parseInt(args[3]); System.out.println("=========================================="); System.out.println("pathin: " + pathin); System.out.println("pathout: " + pathout); System.out.println("nrOfDocuments: " + nrOfDocuments); System.out.println("topN: " + topN); System.out.println("=========================================="); FileSystem fs = FileSystem.get(conf); if (!fs.exists(new Path(pathout))) { fs.mkdirs(new Path(pathout)); } Path firstJobOut = new Path(pathout, "job1_output"); Path secondJobOut = new Path(pathout, "job2_output"); Path thirdJobOut = new Path(pathout, "job3_output"); // empty if exists output fs.delete(firstJobOut, true); fs.delete(secondJobOut, true); fs.delete(thirdJobOut, true); // Run job 1 runFirstJob(new Path(pathin), firstJobOut, nrOfDocuments); // Run job 2 runSecondJob(firstJobOut, secondJobOut, nrOfDocuments); // job1的输出作为job2的输入+ // Run job 3 runThirdJob(secondJobOut, thirdJobOut, topN); // job1的输出作为job2的输入+ } private static int runFirstJob(Path pathin, Path pathout, final int reduceTaskSize) throws Exception { String jobName = "tfidf_first_job"; System.out.println("==================" + jobName + "======================="); Job job = new Job(conf, jobName); job.setJarByClass(TfIdfMapReduce.class); job.setMapperClass(FirstMapReduce.Mapper.class); job.setCombinerClass(FirstMapReduce.Combiner.class); job.setReducerClass(FirstMapReduce.Reducer.class); job.setNumReduceTasks(reduceTaskSize); // 自定义分区器 job.setPartitionerClass(FirstMapReduce.Partitioner.class); job.setInputFormatClass(TextInputFormat.class); job.setOutputFormatClass(TextOutputFormat.class); job.setMapOutputKeyClass(Text.class); job.setMapOutputValueClass(Text.class); job.setOutputKeyClass(Text.class); job.setOutputValueClass(Text.class); FileInputFormat.addInputPath(job, pathin); FileOutputFormat.setOutputPath(job, pathout); boolean success = job.waitForCompletion(true); return success ? 0 : -1; } private static int runSecondJob(Path pathin, Path pathout, final int nrOfDocuments) throws Exception { String jobName = "tfidf_second_job"; System.out.println("==================" + jobName + "======================="); conf.setInt("nrOfDocuments", nrOfDocuments); Job job = new Job(conf, jobName); job.setJarByClass(TfIdfMapReduce.class); job.setMapperClass(SecondMapReduce.Mapper.class); job.setCombinerClass(SecondMapReduce.Combiner.class); job.setReducerClass(SecondMapReduce.Reducer.class); job.setInputFormatClass(KeyValueTextInputFormat.class); job.setOutputFormatClass(TextOutputFormat.class); job.setMapOutputKeyClass(Text.class); job.setMapOutputValueClass(Text.class); job.setOutputKeyClass(Text.class); job.setOutputValueClass(Text.class); FileInputFormat.addInputPath(job, pathin); FileOutputFormat.setOutputPath(job, pathout); boolean success = job.waitForCompletion(true); return success ? 0 : -1; } private static int runThirdJob(Path pathin, Path pathout, final int topN) throws Exception { String jobName = "tfidf_third_job"; System.out.println("==================" + jobName + "======================="); conf.setInt("topN", topN); conf.set("topN_out", new Path(pathin.getParent(), "" + topN).getName()); Job job = new Job(conf, jobName); job.setJarByClass(TfIdfMapReduce.class); job.setMapperClass(ThirdMapReduce.Mapper.class); job.setReducerClass(ThirdMapReduce.Reducer.class); job.setInputFormatClass(KeyValueTextInputFormat.class); job.setOutputFormatClass(TextOutputFormat.class); job.setMapOutputKeyClass(Text.class); job.setMapOutputValueClass(Text.class); job.setOutputKeyClass(Text.class); job.setOutputValueClass(Text.class); MultipleOutputs.addNamedOutput(job, "top" + topN, TextOutputFormat.class, Text.class, Text.class); FileInputFormat.addInputPath(job, pathin); FileOutputFormat.setOutputPath(job, pathout); boolean success = job.waitForCompletion(true); return success ? 0 : -1; } static class FirstMapReduce { // 分词接口 static IWordSegService wordSegService; //停用词过滤接口 static IFilterStopwordService filterStopwordService; static { init(); } static void init() { ApplicationContext ctx = new ClassPathXmlApplicationContext("classpath*:spring/robot-preprocess.xml"); wordSegService = (IWordSegService) ctx.getBean("wordSegService"); filterStopwordService = (IFilterStopwordService) ctx.getBean("filterStopwordService"); } static class Mapper extends org.apache.hadoop.mapreduce.Mapper<LongWritable, Text, Text, Text> { static final Text one = new Text("1"); String filename = ""; long totalWordCount = 0; // 当前文档中单词总数 @Override protected void setup(Context context) throws IOException, InterruptedException { System.out.println("=================" + context.getJobName() + " map================"); } @Override protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException { // Segment the line into words and output each word // Input (LineNr, Line in document) // Output (filename;word, 1) String line = value.toString(); if (line.trim().isEmpty() || line.startsWith("#")) { // ignore empty or comment line return; } FileSplit split = (FileSplit) context.getInputSplit(); filename = split.getPath().toString(); // 分词 Collection<Word> words = wordSegService.segment(line); // 去掉停用词 filterStopwordService.filter(words); for (Word word : words) { String outputKey = filename + ";" + word.getName(); //System.out.println("<" + outputKey + ", " + one.toString() + ">"); context.write(new Text(outputKey), one); ++totalWordCount; } // end for } // end map @Override protected void cleanup(Context context) throws IOException, InterruptedException { context.write(new Text(filename + ";" + "!"), new Text("" + totalWordCount)); // 写入文件中词的总数目, ‘!‘的ascii码比所有字母都小,sort后排在最前面 } } // end class Mapper static class Partitioner extends org.apache.hadoop.mapreduce.Partitioner<Text, Text> { @Override public int getPartition(Text key, Text value, int numPartitions) { // partition by filename StringTokenizer tokenizer = new StringTokenizer(key.toString(), ";"); String filename = tokenizer.nextToken(); int hashCode = new Text(filename).hashCode(); return Math.abs((hashCode * 127) % numPartitions); } } // end class Partitioner static class Combiner extends org.apache.hadoop.mapreduce.Reducer<Text, Text, Text, Text> { @Override protected void setup(Context context) throws IOException, InterruptedException { System.out.println("=================" + context.getJobName() + " combiner================"); } long totalWordCount = 0; @Override protected void reduce(Text key, Iterable<Text> values, Context context) throws IOException, InterruptedException { // Calculate word count of each document and total word count // Input (filename;word, 1) // Output (word;filename, n;N) StringTokenizer tokenizer = new StringTokenizer(key.toString(), ";"); String filename = tokenizer.nextToken(); String word = tokenizer.nextToken(); if(word.endsWith("!")) { for (Text value : values) { totalWordCount = Long.parseLong(value.toString()); System.out.println("File " + filename + " total word count " + totalWordCount); return; } } long wordCount = 0; for(Text value: values) { wordCount += Integer.parseInt(value.toString()); } String outputKey = word + ";" + filename; String outputValue = http://www.mamicode.com/wordCount +";" + totalWordCount; //System.out.println("<" + outputKey + ", " + outputValue + ">"); context.write(new Text(outputKey), new Text(outputValue)); } // end reduce } // end class Combiner static class Reducer extends org.apache.hadoop.mapreduce.Reducer<Text, Text, Text, Text> { @Override protected void setup(Context context) throws IOException, InterruptedException { System.out.println("=================" + context.getJobName() + " reducer================"); } protected void reduce(Text key, Iterable<Text> values, Context context) throws IOException, InterruptedException { for (Text value : values) { //System.out.println("<" + key.toString() + ", " + value.toString() + ">"); context.write(key, value); } } } // end reduce } // end class reducer static class SecondMapReduce { static class Mapper extends org.apache.hadoop.mapreduce.Mapper<Text, Text, Text, Text> { static Text one = new Text("1"); @Override protected void setup(Context context) throws IOException, InterruptedException { System.out.println("=================" + context.getJobName() + " map================"); } @Override protected void map(Text key, Text value, Context context) throws IOException, InterruptedException { // Word occur in document // Input (word;filename, n;N) // Output (word;filename;n;N, 1) String outputKey = key.toString() + ";" + value.toString(); String outputValue = http://www.mamicode.com/one.toString();"<" + outputKey + ", " + outputValue + ">"); context.write(new Text(outputKey), one); } } // end map static class Combiner extends org.apache.hadoop.mapreduce.Reducer<Text, Text, Text, Text> { int D = 1; @Override protected void setup(Context context) throws IOException, InterruptedException { D = context.getConfiguration().getInt("nrOfDocuments", 0); System.out.println("=================" + context.getJobName() + " combiner================"); } protected void reduce(Text key, Iterable<Text> values, Context context) throws IOException, InterruptedException { // Calculate word contains document count // Input (word;filename;n;N, 1) // Output (word;filename;n;N, d;D) int d = 0; // 该单词包含的文档总数 for (Text value : values) { d += Integer.parseInt(value.toString()); } String outputKey = key.toString(); String outputValue = http://www.mamicode.com/d +";" + D; //System.out.println("<" + outputKey + ", " + outputValue + ">"); context.write(key, new Text(outputValue)); } // end reduce } // end class Combiner static class Reducer extends org.apache.hadoop.mapreduce.Reducer<Text, Text, Text, Text> { @Override protected void setup(Context context) throws IOException, InterruptedException { System.out.println("=================" + context.getJobName() + " reducer================"); } protected void reduce(Text key, Iterable<Text> values, Context context) throws IOException, InterruptedException { // Calculate tf-idf // Input (word;filename;n;N, d;D) // Output (word;filename, tf-idf) StringTokenizer keyTokenizer = new StringTokenizer(key.toString(), ";"); String word = keyTokenizer.nextToken(); String filename = keyTokenizer.nextToken(); long n = Long.parseLong(keyTokenizer.nextToken()); // 单词出现次数 long N = Long.parseLong(keyTokenizer.nextToken()); // 单词总数 StringTokenizer valueTokenizer = new StringTokenizer(values.iterator().next().toString(), ";"); int d = Integer.parseInt(valueTokenizer.nextToken()); // 单词包含的文档数 int D = Integer.parseInt(valueTokenizer.nextToken()); // 文档总数 double tf = n / 1.0d / N; double idf = Math.log(D / 1.0d / d); double tfidf = tf * idf; String outputKey = word + ";" + filename; String outputValuehttp://www.mamicode.com/= "" + tfidf; //System.out.println("<" + outputKey + ", " + outputValue + ">"); context.write(new Text(outputKey), new Text(outputValue)); } // end reduce @Override protected void cleanup(Context context) throws IOException, InterruptedException { super.cleanup(context); } } // end Reducer } // end class SecondMapReduce static class ThirdMapReduce { static class Pair implements Comparable<Pair>{ final String key; final Double value; public Pair(String key, Double value) { this.key = key; this.value = http://www.mamicode.com/value;"topN", 100); // default 100 System.out.println("=================" + context.getJobName() + " map================"); } @Override protected void map(Text key, Text value, Context context) throws IOException, InterruptedException { // Input (word;filename, tf-idf) treemap.put(new Pair(key.toString(), Double.parseDouble(value.toString())), value.toString()); if(treemap.size() > topN) { treemap.remove(treemap.lastKey()); } } // end map @Override protected void cleanup(Context context) throws IOException, InterruptedException { Set<Entry<Pair,String>> entrySet = treemap.entrySet(); for (Entry<Pair, String> entry : entrySet) { String outputKey = entry.getKey().toString(); String outputValue = http://www.mamicode.com/entry.getValue();"<" + outputKey + ", " + outputValue + ">"); context.write(new Text(outputKey), new Text(outputValue)); } } } // end class mapper static class Reducer extends org.apache.hadoop.mapreduce.Reducer<Text, Text, Text, Text> { int topN; static TreeMap<Pair, String> treemap = new TreeMap<Pair, String>(new Comparator<Pair>() { public int compare(Pair o1, Pair o2) { return o1.compareTo(o2); } }); @Override protected void setup(Context context) throws IOException, InterruptedException { topN = context.getConfiguration().getInt("topN", 100); // default 100 System.out.println("=================" + context.getJobName() + " reduce================"); } @Override protected void reduce(Text key, Iterable<Text> values,Context context) throws IOException, InterruptedException { // Input (word;filename, tf-idf) Text value = http://www.mamicode.com/values.iterator().next();"topN_out"); MultipleOutputs<Text, Text> output = null; try { output = new MultipleOutputs<Text, Text>(context); Set<Entry<Pair, String>> entrySet = treemap.entrySet(); System.out.println("================TF-IDF top " + topN + "=================="); for (Entry<Pair, String> entry : entrySet) { String key = entry.getKey().toString(); String value = http://www.mamicode.com/entry.getValue();"top" + topN, key, value, path); System.out.println("<" + key + ", " + value + ">"); } } catch (IOException e) { throw e; } catch (InterruptedException e) { throw e; } finally { if (output != null) { output.close(); } } } } // end class Reducer } }
tf-idf hadoop map reduce
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