crimesbymonthineachyear.CrimesByMonthInEachYear.java Source code

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Here is the source code for crimesbymonthineachyear.CrimesByMonthInEachYear.java

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/*
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package crimesbymonthineachyear;

import java.io.IOException;
import java.util.Iterator;
import java.util.StringTokenizer;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.KeyValueTextInputFormat;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.TextOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

/**
 *
 * @author Sattya
 */
public class CrimesByMonthInEachYear extends Configured implements Tool {

    public static class MapClass extends MapReduceBase implements Mapper<Text, Text, Text, IntWritable> {
        private static final IntWritable one = new IntWritable(1);
        private Text word = new Text();

        public void map(Text key, Text value, OutputCollector<Text, IntWritable> output, Reporter reporter)
                throws IOException {
            String line = key.toString();
            if (line != null) {
                String[] cols = line.split(",");
                try {
                    String date = cols[2];
                    Pattern p = Pattern.compile("(\\d*)/(\\d*)/(\\d*)\\s*(\\d*):(\\d*)");
                    Matcher m = p.matcher(date);
                    if (m.find()) {
                        String month = getMonth(m.group(1));
                        String year = "20" + m.group(3);
                        word.set(month + "_" + year);
                        output.collect(word, one);
                    }
                } catch (Exception e) {
                    System.out.println("Bad row: " + e);
                }
            }
        }

        public String getMonth(String month) {

            switch (month) {
            case "1":
                return "Jan";
            case "01":
                return "Jan";
            case "2":
                return "Feb";
            case "02":
                return "Feb";
            case "3":
                return "Mar";
            case "03":
                return "Mar";
            case "4":
                return "Apr";
            case "04":
                return "Apr";
            case "5":
                return "May";
            case "05":
                return "May";
            case "6":
                return "Jun";
            case "06":
                return "Jun";
            case "7":
                return "Jul";
            case "07":
                return "Jul";
            case "8":
                return "Aug";
            case "08":
                return "Aug";
            case "9":
                return "Sep";
            case "09":
                return "Sep";
            case "10":
                return "Oct";
            case "11":
                return "Nov";
            case "12":
                return "Dec";
            default:
                return "Invalid month";
            }
        }
    }

    public static class Reduce extends MapReduceBase implements Reducer<Text, IntWritable, Text, IntWritable> {

        public void reduce(Text key, Iterator<IntWritable> values, OutputCollector<Text, IntWritable> output,
                Reporter reporter) throws IOException {
            int sum = 0;
            while (values.hasNext()) {
                sum += ((IntWritable) values.next()).get();
            }
            output.collect(key, new IntWritable(sum));

        }

    }

    public int run(String[] args) throws Exception {
        Configuration conf = getConf();

        JobConf job = new JobConf(conf, CrimesByMonthInEachYear.class);

        Path in = new Path(args[0]);
        Path out = new Path(args[1]);
        FileInputFormat.setInputPaths(job, in);
        FileOutputFormat.setOutputPath(job, out);

        job.setJobName("CrimesByMonthInEachYear");
        job.setMapperClass(MapClass.class);
        job.setReducerClass(Reduce.class);

        job.setInputFormat(KeyValueTextInputFormat.class);
        job.setOutputFormat(TextOutputFormat.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        //   job.set("key.value.separator.in.input.line", "");

        JobClient.runJob(job);

        return 0;
    }

    public static void main(String[] args) throws Exception {
        int res = ToolRunner.run(new Configuration(), new CrimesByMonthInEachYear(), args);
        System.exit(res);
    }
}