package hip.ch6.sort.total;
import hip.ch6.sort.secondary.*;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
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.input.KeyValueTextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import java.io.IOException;
public final class SampleMapReduce {
public static void main(String... args) throws Exception {
runSortJob(args[0], args[1]);
}
public static void runSortJob(String input, String output)
throws Exception {
Configuration conf = new Configuration();
Job job = new Job(conf);
job.setJarByClass(SampleMapReduce.class);
job.setMapperClass(Map.class);
job.setReducerClass(Reduce.class);
job.setInputFormatClass(KeyValueTextInputFormat.class);
job.setMapOutputKeyClass(Person.class);
job.setMapOutputValueClass(Text.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(Text.class);
job.setPartitionerClass(PersonNamePartitioner.class);
job.setSortComparatorClass(PersonComparator.class);
job.setGroupingComparatorClass(PersonNameComparator.class);
Path outputPath = new Path(output);
FileInputFormat.setInputPaths(job, input);
FileOutputFormat.setOutputPath(job, outputPath);
outputPath.getFileSystem(conf).delete(outputPath, true);
job.waitForCompletion(true);
}
public static class Map
extends Mapper<Text, Text, Person, Text> {
private Person outputKey = new Person();
@Override
protected void map(Text lastName, Text firstName, Context context)
throws IOException, InterruptedException {
outputKey.set(lastName.toString(), firstName.toString());
context.write(outputKey, firstName);
}
}
public static class Reduce
extends Reducer<Person, Text, Text, Text> {
Text lastName = new Text();
@Override
public void reduce(Person key, Iterable<Text> values,
Context context)
throws IOException, InterruptedException {
lastName.set(key.getLastName());
for (Text firstName : values) {
context.write(lastName, firstName);
}
}
}
}