FlightData.Taxi.java Source code

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Here is the source code for FlightData.Taxi.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package FlightData;

import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.DoubleWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
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 Taxi {

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

        private Text orig = new Text();
        private Text dest = new Text();

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

            if (key.get() > 0) {
                int taxiIn = 0;
                int taxiOut = 0;
                String line = null;
                line = value.toString();
                String str[] = line.split(",");
                try {
                    taxiIn = Integer.parseInt(str[19]);
                    taxiOut = Integer.parseInt(str[20]);
                    orig.set(str[16]);
                    dest.set(str[17]);

                    context.write(orig, new Text(taxiOut + ",1"));
                    context.write(dest, new Text(taxiIn + ",1"));

                } catch (java.lang.NumberFormatException e) {
                    return;
                }

            }

        }
    }

    public static class TaxiCombiner extends Reducer<Text, Text, Text, Text> {

        public void reduce(Text key, Iterable<Text> value, Context context)
                throws IOException, InterruptedException {
            int totalTaxi = 0;
            int count = 0;
            for (Text val : value) {
                String[] s1 = val.toString().split(",");
                totalTaxi += Integer.parseInt(s1[0]);
                count += Integer.parseInt(s1[1]);
            }
            System.out.println("Combine" + (new String(totalTaxi + "," + count)));
            context.write(key, new Text(new String(totalTaxi + "," + count)));

        }
    }

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

        public void reduce(Text key, Iterable<Text> values, Context context)
                throws IOException, InterruptedException {
            int sum = 0;
            int count = 0;
            for (Text val : values) {
                String[] s = val.toString().split(",");
                sum += Integer.parseInt(s[0]);
                count += Integer.parseInt(s[1]);
            }

            context.write(key, new DoubleWritable(sum * 1.0 / count));
        }
    }

    public static void main(String[] args) throws Exception {
        Configuration conf = new Configuration();
        String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
        if (otherArgs.length < 2) {
            System.err.println("Usage: Taxi <in> [<in>...] <out>");
            System.exit(2);
        }
        Job job = Job.getInstance(conf, "Taxi Time");
        job.setJarByClass(Taxi.class);
        job.setMapperClass(TaxiMapper.class);
        job.setCombinerClass(TaxiCombiner.class);
        job.setReducerClass(TaxiReducer.class);
        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(Text.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        for (int i = 0; i < otherArgs.length - 1; ++i) {
            FileInputFormat.addInputPath(job, new Path(otherArgs[i]));
        }
        FileOutputFormat.setOutputPath(job, new Path(otherArgs[otherArgs.length - 1]));
        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }
}