WordCount 远程集群源码

package test;

import java.io.IOException;

import java.util.StringTokenizer;

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.util.GenericOptionsParser;

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

      while (itr.hasMoreTokens()) {

        word.set(itr.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) throws Exception {

    Configuration conf = new Configuration();

    //conf.set("mapred.job.tracker", "192.168.2.35:9001");

  //在你的文件地址前自动添加：hdfs://master:9000/

    //conf.set("fs.defaultFS", "hdfs://192.168.2.35:9001/");

    //conf.set("hadoop.job.user","hadoop");

    //指定jobtracker的ip和端口号，master在/etc/hosts中可以配置

    //conf.set("mapred.job.tracker","192.168.2.35:9001");

    //在你的文件地址前自动添加：hdfs://master:9000/

    conf.set("fs.defaultFS", "hdfs://192.168.2.35:9000/");

    ////conf.set("hadoop.job.user","hadoop");

   //// conf.set("Master","1234");

    //指定jobtracker的ip和端口号，master在/etc/hosts中可以配置

    //////conf.set("mapred.job.tracker","Master:9001");

    String[] ars=new String[]{"input","out"};

    String[] otherArgs = new GenericOptionsParser(conf, ars).getRemainingArgs();

    if (otherArgs.length != 2) {

      System.err.println("Usage: wordcount  ");

      System.exit(2);

    }

    Job job = new Job(conf, "wordcount");

    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(otherArgs[0]));

    FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));

    System.exit(job.waitForCompletion(true) ? 0 : 1);

  }

}