1 | import java.io.*; |
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2 | import java.util.*; |
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3 | |
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4 | import org.apache.hadoop.fs.Path; |
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5 | import org.apache.hadoop.filecache.DistributedCache; |
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6 | import org.apache.hadoop.conf.*; |
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7 | import org.apache.hadoop.io.*; |
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8 | import org.apache.hadoop.mapred.*; |
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9 | import org.apache.hadoop.util.*; |
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10 | |
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11 | public class WordCount2 extends Configured implements Tool { |
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12 | |
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13 | public static class Map extends MapReduceBase implements Mapper<LongWritable, Text, Text, IntWritable> { |
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14 | |
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15 | static enum Counters { INPUT_WORDS } |
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16 | |
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17 | private final static IntWritable one = new IntWritable(1); |
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18 | private Text word = new Text(); |
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19 | |
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20 | private boolean caseSensitive = true; |
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21 | private Set<String> patternsToSkip = new HashSet<String>(); |
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22 | |
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23 | private long numRecords = 0; |
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24 | private String inputFile; |
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25 | |
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26 | public void configure(JobConf job) { |
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27 | caseSensitive = job.getBoolean("wordcount.case.sensitive", true); |
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28 | inputFile = job.get("map.input.file"); |
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29 | |
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30 | if (job.getBoolean("wordcount.skip.patterns", false)) { |
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31 | Path[] patternsFiles = new Path[0]; |
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32 | try { |
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33 | patternsFiles = DistributedCache.getLocalCacheFiles(job); |
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34 | } catch (IOException ioe) { |
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35 | System.err.println("Caught exception while getting cached files: " + StringUtils.stringifyException(ioe)); |
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36 | } |
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37 | for (Path patternsFile : patternsFiles) { |
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38 | parseSkipFile(patternsFile); |
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39 | } |
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40 | } |
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41 | } |
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42 | |
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43 | private void parseSkipFile(Path patternsFile) { |
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44 | try { |
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45 | BufferedReader fis = new BufferedReader(new FileReader(patternsFile.toString())); |
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46 | String pattern = null; |
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47 | while ((pattern = fis.readLine()) != null) { |
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48 | patternsToSkip.add(pattern); |
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49 | } |
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50 | } catch (IOException ioe) { |
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51 | System.err.println("Caught exception while parsing the cached file '" + patternsFile + "' : " + StringUtils.stringifyException(ioe)); |
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52 | } |
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53 | } |
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54 | |
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55 | public void map(LongWritable key, Text value, OutputCollector<Text, IntWritable> output, Reporter reporter) throws IOException { |
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56 | String line = (caseSensitive) ? value.toString() : value.toString().toLowerCase(); |
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57 | |
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58 | for (String pattern : patternsToSkip) { |
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59 | line = line.replaceAll(pattern, ""); |
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60 | } |
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61 | |
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62 | StringTokenizer tokenizer = new StringTokenizer(line); |
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63 | while (tokenizer.hasMoreTokens()) { |
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64 | word.set(tokenizer.nextToken()); |
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65 | output.collect(word, one); |
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66 | reporter.incrCounter(Counters.INPUT_WORDS, 1); |
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67 | } |
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68 | |
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69 | if ((++numRecords % 100) == 0) { |
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70 | reporter.setStatus("Finished processing " + numRecords + " records " + "from the input file: " + inputFile); |
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71 | } |
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72 | } |
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73 | } |
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74 | |
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75 | public static class Reduce extends MapReduceBase implements Reducer<Text, IntWritable, Text, IntWritable> { |
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76 | public void reduce(Text key, Iterator<IntWritable> values, OutputCollector<Text, IntWritable> output, Reporter reporter) throws IOException { |
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77 | int sum = 0; |
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78 | while (values.hasNext()) { |
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79 | sum += values.next().get(); |
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80 | } |
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81 | output.collect(key, new IntWritable(sum)); |
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82 | } |
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83 | } |
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84 | |
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85 | public int run(String[] args) throws Exception { |
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86 | JobConf conf = new JobConf(getConf(), WordCount2.class); |
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87 | conf.setJobName("wordcount"); |
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88 | |
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89 | conf.setOutputKeyClass(Text.class); |
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90 | conf.setOutputValueClass(IntWritable.class); |
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91 | |
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92 | conf.setMapperClass(Map.class); |
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93 | conf.setCombinerClass(Reduce.class); |
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94 | conf.setReducerClass(Reduce.class); |
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95 | |
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96 | conf.setInputFormat(TextInputFormat.class); |
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97 | conf.setOutputFormat(TextOutputFormat.class); |
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98 | |
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99 | List<String> other_args = new ArrayList<String>(); |
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100 | for (int i=0; i < args.length; ++i) { |
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101 | if ("-skip".equals(args[i])) { |
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102 | DistributedCache.addCacheFile(new Path(args[++i]).toUri(), conf); |
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103 | conf.setBoolean("wordcount.skip.patterns", true); |
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104 | } else { |
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105 | other_args.add(args[i]); |
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106 | } |
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107 | } |
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108 | |
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109 | FileInputFormat.setInputPaths(conf, new Path(other_args.get(0))); |
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110 | FileOutputFormat.setOutputPath(conf, new Path(other_args.get(1))); |
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111 | |
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112 | JobClient.runJob(conf); |
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113 | return 0; |
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114 | } |
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115 | |
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116 | public static void main(String[] args) throws Exception { |
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117 | int res = ToolRunner.run(new Configuration(), new WordCount2(), args); |
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118 | System.exit(res); |
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119 | } |
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120 | } |
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