HadoopWordCount.java

public class WordCount {
           
    public static class Map extends Mapper<LongWritable, Text, Text, IntWritable> {
        private final static IntWritable one = new IntWritable(1);
        private Text word = new Text();
           
        public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
            String line = value.toString();
            StringTokenizer tokenizer = new StringTokenizer(line);
            while (tokenizer.hasMoreTokens()) {
                word.set(tokenizer.nextToken());
                context.write(word, one);
            }
        }
    } 
           
    public static class Reduce extends Reducer<Text, IntWritable, Text, IntWritable> {
   
        public void reduce(Text key, Iterable<IntWritable> values, Context context) 
            throws IOException, InterruptedException {
            int sum = 0;
            for (IntWritable val : values) {
                sum += val.get();
            }
            context.write(key, new IntWritable(sum));
        }
    }
           
    public static void main(String[] args) throws Exception {
        Configuration conf = new Configuration();
           
        Job job = new Job(conf, "wordcount");
       
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
           
        job.setMapperClass(Map.class);
        job.setReducerClass(Reduce.class);
           
        job.setInputFormatClass(TextInputFormat.class);
        job.setOutputFormatClass(TextOutputFormat.class);
           
        FileInputFormat.addInputPath(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[1]));
           
        job.waitForCompletion(true);
    }
           
}