[24] | 1 | import java.io.BufferedReader; |
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| 2 | import java.io.FileReader; |
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| 3 | import java.io.IOException; |
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| 4 | import java.util.HashSet; |
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| 5 | import java.util.Iterator; |
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| 6 | import java.util.Set; |
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| 7 | import java.util.StringTokenizer; |
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| 8 | |
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| 9 | import org.apache.hadoop.conf.Configured; |
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| 10 | import org.apache.hadoop.filecache.DistributedCache; |
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| 11 | import org.apache.hadoop.fs.FileSystem; |
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| 12 | import org.apache.hadoop.fs.Path; |
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| 13 | import org.apache.hadoop.io.IntWritable; |
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| 14 | import org.apache.hadoop.io.LongWritable; |
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| 15 | import org.apache.hadoop.io.Text; |
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| 16 | import org.apache.hadoop.mapred.FileInputFormat; |
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| 17 | import org.apache.hadoop.mapred.FileOutputFormat; |
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| 18 | import org.apache.hadoop.mapred.JobClient; |
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| 19 | import org.apache.hadoop.mapred.JobConf; |
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| 20 | import org.apache.hadoop.mapred.MapReduceBase; |
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| 21 | import org.apache.hadoop.mapred.Mapper; |
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| 22 | import org.apache.hadoop.mapred.OutputCollector; |
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| 23 | import org.apache.hadoop.mapred.Reducer; |
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| 24 | import org.apache.hadoop.mapred.Reporter; |
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| 25 | import org.apache.hadoop.util.StringUtils; |
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| 26 | |
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| 27 | public class WordCount2 extends Configured { |
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| 28 | |
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| 29 | public static class Map extends MapReduceBase implements |
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| 30 | Mapper<LongWritable, Text, Text, IntWritable> { |
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| 31 | |
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| 32 | static enum Counters { |
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| 33 | INPUT_WORDS |
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| 34 | } |
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| 35 | |
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| 36 | private final static IntWritable one = new IntWritable(1); |
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| 37 | |
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| 38 | private Text word = new Text(); |
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| 39 | |
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| 40 | private boolean caseSensitive = true; |
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| 41 | |
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| 42 | private Set<String> patternsToSkip = new HashSet<String>(); |
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| 43 | |
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| 44 | private long numRecords = 0; |
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| 45 | |
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| 46 | private String inputFile; |
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| 47 | |
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| 48 | public void configure(JobConf job) { |
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| 49 | caseSensitive = job.getBoolean("wordcount.case.sensitive", true); |
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| 50 | inputFile = job.get("map.input.file"); |
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| 51 | |
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| 52 | if (job.getBoolean("wordcount.skip.patterns", false)) { |
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| 53 | Path[] patternsFiles = new Path[0]; |
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| 54 | try { |
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| 55 | patternsFiles = DistributedCache.getLocalCacheFiles(job); |
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| 56 | } catch (IOException ioe) { |
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| 57 | System.err |
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| 58 | .println("Caught exception while getting cached files: " |
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| 59 | + StringUtils.stringifyException(ioe)); |
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| 60 | } |
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| 61 | for (Path patternsFile : patternsFiles) { |
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| 62 | parseSkipFile(patternsFile); |
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| 63 | } |
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| 64 | } |
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| 65 | } |
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| 66 | |
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| 67 | private void parseSkipFile(Path patternsFile) { |
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| 68 | try { |
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| 69 | BufferedReader fis = new BufferedReader(new FileReader( |
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| 70 | patternsFile.toString())); |
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| 71 | String pattern = null; |
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| 72 | while ((pattern = fis.readLine()) != null) { |
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| 73 | patternsToSkip.add(pattern); |
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| 74 | } |
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| 75 | } catch (IOException ioe) { |
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| 76 | System.err |
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| 77 | .println("Caught exception while parsing the cached file '" |
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| 78 | + patternsFile |
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| 79 | + "' : " |
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| 80 | + StringUtils.stringifyException(ioe)); |
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| 81 | } |
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| 82 | } |
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| 83 | |
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| 84 | public void map(LongWritable key, Text value, |
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| 85 | OutputCollector<Text, IntWritable> output, Reporter reporter) |
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| 86 | throws IOException { |
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| 87 | String line = (caseSensitive) ? value.toString() : value.toString() |
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| 88 | .toLowerCase(); |
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| 89 | |
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| 90 | for (String pattern : patternsToSkip) { |
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| 91 | line = line.replaceAll(pattern, ""); |
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| 92 | } |
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| 93 | |
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| 94 | StringTokenizer tokenizer = new StringTokenizer(line); |
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| 95 | while (tokenizer.hasMoreTokens()) { |
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| 96 | word.set(tokenizer.nextToken()); |
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| 97 | output.collect(word, one); |
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| 98 | reporter.incrCounter(Counters.INPUT_WORDS, 1); |
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| 99 | } |
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| 100 | |
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| 101 | if ((++numRecords % 100) == 0) { |
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| 102 | reporter.setStatus("Finished processing " + numRecords |
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| 103 | + " records " + "from the input file: " + inputFile); |
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| 104 | } |
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| 105 | } |
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| 106 | } |
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| 107 | |
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| 108 | public static class Reduce extends MapReduceBase implements |
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| 109 | Reducer<Text, IntWritable, Text, IntWritable> { |
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| 110 | public void reduce(Text key, Iterator<IntWritable> values, |
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| 111 | OutputCollector<Text, IntWritable> output, Reporter reporter) |
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| 112 | throws IOException { |
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| 113 | int sum = 0; |
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| 114 | while (values.hasNext()) { |
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| 115 | sum += values.next().get(); |
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| 116 | } |
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| 117 | output.collect(key, new IntWritable(sum)); |
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| 118 | } |
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| 119 | } |
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| 120 | |
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| 121 | public static void main(String[] args) throws IOException { |
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| 122 | String filename = "/user/waue/input/"; |
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| 123 | String outputPath = "sample-counts"; |
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| 124 | int mapTasks = 20; |
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| 125 | int reduceTasks = 1; |
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| 126 | |
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| 127 | JobConf conf = new JobConf(WordCount2.class); |
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| 128 | conf.setJobName("wordcount"); |
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| 129 | |
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| 130 | conf.setNumMapTasks(mapTasks); |
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| 131 | conf.setNumReduceTasks(reduceTasks); |
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| 132 | |
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| 133 | // conf.setInputPath(new Path(filename)); |
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| 134 | FileInputFormat.setInputPaths(conf,new Path(filename)); |
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| 135 | conf.setOutputKeyClass(Text.class); |
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| 136 | conf.setOutputValueClass(IntWritable.class); |
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| 137 | |
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| 138 | // conf.setOutputPath(new Path(outputPath)); |
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| 139 | FileOutputFormat.setOutputPath( conf, new Path(filename)); |
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| 140 | |
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| 141 | |
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| 142 | conf.setMapperClass(Map.class); |
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| 143 | conf.setCombinerClass(Reduce.class); |
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| 144 | conf.setReducerClass(Reduce.class); |
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| 145 | |
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| 146 | // Delete the output directory if it exists already |
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| 147 | Path outputDir = new Path(outputPath); |
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| 148 | FileSystem.get(conf).delete(outputDir,true); |
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| 149 | JobClient.runJob(conf); |
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| 150 | } |
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| 151 | } |
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