MapReduce/Nasdaq1.java at master · rajesh1980/MapReduce · GitHub

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package com.Rajesh.mapreduce;

import java.io.IOException;


import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.*;
import org.apache.hadoop.mapreduce.*;
import org.apache.hadoop.conf.*;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;


public class Nasdaq1 {

public static class MyMapper extends Mapper<LongWritable, Text, Text, LongWritable> {


		public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException{

		      String line = value.toString();
		      String[] column = line.split(",");

		      String stockColHeader = "stock_symbol" ;
		      String stockSymbol = column[1] ;
		      String stockVolume = column[7] ;

		    	if(stockSymbol.compareTo(stockColHeader) != 0) {
		      	context.write(new Text(stockSymbol), new LongWritable(Long.parseLong(stockVolume)));
		    	}
		}

	}

public static class MyReducer extends Reducer<Text, LongWritable, Text, LongWritable> {

	public void reduce(Text key, Iterable<LongWritable> values, Context context) throws IOException, InterruptedException{

		long sum = 0;

		for(LongWritable val : values) {

			sum = sum + val.get() ;
			}
        context.write(key, new LongWritable(sum));

		}

	}


public static void main(String[] args) throws Exception {

		Configuration conf = new Configuration();
		Job job = new Job(conf, "Nasdaq1");
		job.setJarByClass(Nasdaq1.class);


		job.setMapperClass(MyMapper.class);
		job.setReducerClass(MyReducer.class);

		job.setMapOutputKeyClass(Text.class);
		job.setMapOutputValueClass(LongWritable.class);

		job.setOutputKeyClass(Text.class);
		job.setOutputValueClass(LongWritable.class);

		FileInputFormat.addInputPath(job, new Path(args[0]));
		FileOutputFormat.setOutputPath(job, new Path(args[1]));

		job.waitForCompletion(true);
	}
}