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);
  }
}