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Hi I am trying to find average of few numbers using map reduce technique in stand alone mode. I have two input files.It contain values file1: 25 25 25 25 25 and file2: 15 15 15 15 15. My program is working fine but the output file contains output of the mapper instead of reducer output.

Here is my code :

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.io.Writable;
import java.io.*;


    public class Average {

        public static class SumCount implements Writable {

            public int sum;
            public int count;

            @Override
            public void write(DataOutput out) throws IOException {
                out.writeInt(sum);
                out.writeInt(count);
            }

            @Override
            public void readFields(DataInput in) throws IOException {
                sum = in.readInt();
                count =in.readInt();
            }  
        }
      public static class TokenizerMapper extends Mapper<Object, Text, Text, Object>{

        private final static IntWritable valueofkey = new IntWritable();
        private Text word = new Text();
        SumCount sc=new SumCount();
        public void map(Object key, Text value, Context context
                        ) throws IOException, InterruptedException {
          StringTokenizer itr = new StringTokenizer(value.toString());
          int sum=0;
          int count=0;
          int v;
          while (itr.hasMoreTokens()) {
            word.set(itr.nextToken());
            v=Integer.parseInt(word.toString());
            count=count+1;
            sum=sum+v;       
          }
          word.set("average");
          sc.sum=sum;
          sc.count=count;
          context.write(word,sc);
        }
      }

      public static class IntSumReducer extends Reducer<Text,Object,Text,IntWritable> {
        private IntWritable result = new IntWritable();
        public void reduce(Text key, Iterable<SumCount> values,Context context) throws IOException, InterruptedException {
          int sum = 0;
          int count=0;
          int wholesum=0;
          int wholecount=0;
          for (SumCount val : values) {
            wholesum=wholesum+val.sum;
            wholecount=wholecount+val.count;
          }
          int res=wholesum/wholecount;
          result.set(res);
          context.write(key, result );
        }
      }

      public static void main(String[] args) throws Exception {
        Configuration conf = new Configuration();
        Job job = Job.getInstance(conf, "");
        job.setJarByClass(Average.class);
        job.setMapperClass(TokenizerMapper.class);
        job.setCombinerClass(IntSumReducer.class);
        job.setReducerClass(IntSumReducer.class);
        job.setOutputKeyClass(Text.class);
        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(SumCount.class);
        job.setOutputValueClass(IntWritable.class);
        FileInputFormat.addInputPath(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[1]));
        System.exit(job.waitForCompletion(true) ? 0 : 1);
      }
    }

after i run the program my output file is like this:

average Average$SumCount@434ba039
average Average$SumCount@434ba039

asked 38 secs ago

برچسب: نویسنده: استخدام کار تاريخ: دوشنبه 14 تير 1395 ساعت: 12:56

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