兴来每独往，胜事空自知。行到水穷处，坐看云起时

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.reduce.IntSumReducer;

import java.io.IOException;
import java.util.StringTokenizer;


/**
 * Created by Administrator on 2016/5/31 0031.
 */
public class WordCount  {

    public static class TokenizerMapper extends Mapper<Object, Text, Text, IntWritable> {
        private final static IntWritable one = new IntWritable(1);
        private Text word = new Text();

        public void map(Object key, Text value, Context context) throws IOException, InterruptedException {
            StringTokenizer stringTokenizer = new StringTokenizer(value.toString());
            while (stringTokenizer.hasMoreTokens()) {
                word.set(stringTokenizer.nextToken());
                context.write(word, one);
            }
        }
        public static class IntSumReducer  extends Reducer<Text,IntWritable,Text,IntWritable> {
            private IntWritable result = new IntWritable();

            public void reduce(Text key, Iterable<IntWritable> values,   Context context ) throws IOException, InterruptedException {
                int sum = 0;
                for (IntWritable val : values) {
                    sum += val.get();
                }
                result.set(sum);
                context.write(key, result);
            }
        }
    }

    public static void main(String[] args) {
        Configuration conf = new Configuration();
        conf.set("dfs.permissions","false");
        conf.set("fs.default.name", "hdfs://192.168.169.148:9000");
        conf.set("hadoop.job.user", "root");
        conf.set("mapred.job.tracker", "192.168.169.148:9001");
        conf.set("mapred.jar","G:\\study\\workspace\\hadooptest\\output\\hadoopTest.jar");
        try {
            Job job = Job.getInstance(conf, "word count");
            job.setJarByClass(WordCount.class);
            job.setMapperClass(TokenizerMapper.class);
            job.setCombinerClass(IntSumReducer.class);
            job.setReducerClass(IntSumReducer.class);
            job.setOutputKeyClass(Text.class);
            job.setOutputValueClass(IntWritable.class);
//        FileInputFormat.addInputPath(job, new Path(args[0]));
//        FileOutputFormat.setOutputPath(job, new Path(args[1]));
            FileInputFormat.addInputPath(job, new Path("hdfs://192.168.169.148:9000/wordcount/input"));
            FileOutputFormat.setOutputPath(job, new Path("hdfs://192.168.169.148:9000/wordcount/output"));
            System.exit(job.waitForCompletion(true) ? 0 : 1);
        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
}