MapReduce/Nasdaq2.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 Nasdaq2 {

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


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


		      String stockColHeader = "stock_symbol" ;

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

		      String stockSymbol = column[1] ;
		      String stockHigh   = column[4] ;
		      String stockVolume = column[7] ;


		    	if(stockSymbol.compareTo(stockColHeader) != 0 && Long.parseLong(stockVolume) > 300000) {
				    String stockYearMonth   = column[2].substring(0, 7);
		    		context.write(new Text(stockSymbol + "-" + stockYearMonth), new DoubleWritable(Double.parseDouble(stockHigh)));
		    	}
		}

	}

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

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

		double high = 0;
		double currhigh = 0;

		for(DoubleWritable val : values) {

			currhigh = val.get();

			if (currhigh > high) {
				high = currhigh ;
			}
			}
        context.write(key, new DoubleWritable(high));

		}

	}


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

		Configuration conf = new Configuration();
		Job job = new Job(conf, "Nasdaq2");

		job.setJarByClass(Nasdaq2.class);


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

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

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

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

		job.waitForCompletion(true);
	}
}