Hadoop MR Count Word

MRCountWord.java

public class CountWordsMapper extends Mapper<LongWritable, Text, Text, IntWritable> {

    @Override
    public void map(LongWritable key, Text value, Context context) throws 
                     IOException, InterruptedException {

        String line = value.toString();
        StringTokenizer itr = new StringTokenizer(line);

        while (itr.hasMoreTokens()) {
            context.write(new Text(itr.nextToken()), new IntWritable(1));
        }
    }
}

public class CountWordsReducer extends Reducer<Text, IntWritable, Text, IntWritable> {

    @Override
    public void reduce(Text key, Iterable<IntWritable> values, Context context) 
                  throws IOException, InterruptedException {

        int sum = 0;
        for (IntWritable value : values) {
            sum += value.get();
        }
        context.write(key, new IntWritable(sum));
    }
}

public static void main(String[] args) throws Exception {
        if (args.length != 2) {
          System.err.println("Usage: CountWords <input path> <output path>");
          System.exit(-1);
        }
        
        Job job = new Job();
        job.setJarByClass(CountWords.class);
        job.setJobName("Count Words");

        FileInputFormat.addInputPath(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[1]));
        
        job.setMapperClass(CountWordsMapper.class);
        job.setReducerClass(CountWordsReducer.class);

        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        
        System.exit(job.waitForCompletion(true) ? 0 : 1);
      }