Hadoop 의 - 사용자 정의 정렬 알고리즘 정렬 기능 구현
:http://blog.csdn.net/l1028386804/article/details/46288107
먼저 첫 번 째 열 오름차 순 으로 배열 하고 첫 번 째 열 이 동시에 두 번 째 열 오름차 순 으로 배열 해 야 한다.긴 말 하지 않 고 바로 코드 를 올리다
1. Mapper 류 의 실현
/**
* Mapper
* @author liuyazhuang
*
*/
static class MyMapper extends Mapper{
protected void map(LongWritable key, Text value, org.apache.hadoop.mapreduce.Mapper.Context context) throws java.io.IOException ,InterruptedException {
final String[] splited = value.toString().split("\t");
final NewK2 k2 = new NewK2(Long.parseLong(splited[0]), Long.parseLong(splited[1]));
final LongWritable v2 = new LongWritable(Long.parseLong(splited[1]));
context.write(k2, v2);
};
}
2. Reducer 류 의 실현
/**
* Reducer
* @author liuyazhuang
*
*/
static class MyReducer extends Reducer{
protected void reduce(NewK2 k2, java.lang.Iterable v2s, org.apache.hadoop.mapreduce.Reducer.Context context) throws java.io.IOException ,InterruptedException {
context.write(new LongWritable(k2.first), new LongWritable(k2.second));
};
}
3. Writable Comparable 실현
/**
* : ?
* : v2 , k2 v2 , k2
* @author liuyazhuang
*/
static class NewK2 implements WritableComparable{
Long first;
Long second;
public NewK2(){}
public NewK2(long first, long second){
this.first = first;
this.second = second;
}
@Override
public void readFields(DataInput in) throws IOException {
this.first = in.readLong();
this.second = in.readLong();
}
@Override
public void write(DataOutput out) throws IOException {
out.writeLong(first);
out.writeLong(second);
}
/**
* k2 , .
* , ; ,
* @author liuyazhuang
*/
@Override
public int compareTo(NewK2 o) {
final long minus = this.first - o.first;
if(minus !=0){
return (int)minus;
}
return (int)(this.second - o.second);
}
@Override
public int hashCode() {
return this.first.hashCode()+this.second.hashCode();
}
@Override
public boolean equals(Object obj) {
if(!(obj instanceof NewK2)){
return false;
}
NewK2 oK2 = (NewK2)obj;
return (this.first==oK2.first)&&(this.second==oK2.second);
}
}
4. 프로그램 입구 Main
public static void main(String[] args) throws Exception{
final Configuration configuration = new Configuration();
final FileSystem fileSystem = FileSystem.get(new URI(INPUT_PATH), configuration);
if(fileSystem.exists(new Path(OUT_PATH))){
fileSystem.delete(new Path(OUT_PATH), true);
}
final Job job = new Job(configuration, SortApp.class.getSimpleName());
//1.1
FileInputFormat.setInputPaths(job, INPUT_PATH);
//
job.setInputFormatClass(TextInputFormat.class);
//1.2 Mapper
job.setMapperClass(MyMapper.class);
//
job.setMapOutputKeyClass(NewK2.class);
job.setMapOutputValueClass(LongWritable.class);
//1.3
job.setPartitionerClass(HashPartitioner.class);
job.setNumReduceTasks(1);
//1.4 TODO 、
//1.5 TODO ( )
//2.2 reduce
job.setReducerClass(MyReducer.class);
//
job.setOutputKeyClass(LongWritable.class);
job.setOutputValueClass(LongWritable.class);
//2.3
FileOutputFormat.setOutputPath(job, new Path(OUT_PATH));
//
job.setOutputFormatClass(TextOutputFormat.class);
// JobTracker
job.waitForCompletion(true);
}
5. 전체 코드
package com.lyz.hadoop.sort;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.net.URI;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.WritableComparable;
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.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.mapreduce.lib.partition.HashPartitioner;
/**
* Hadoop
* , ,
* @author liuyazhuang
*
*/
public class SortApp {
static final String INPUT_PATH = "hdfs://liuyazhuang:9000/input";
static final String OUT_PATH = "hdfs://liuyazhuang:9000/out";
public static void main(String[] args) throws Exception{
final Configuration configuration = new Configuration();
final FileSystem fileSystem = FileSystem.get(new URI(INPUT_PATH), configuration);
if(fileSystem.exists(new Path(OUT_PATH))){
fileSystem.delete(new Path(OUT_PATH), true);
}
final Job job = new Job(configuration, SortApp.class.getSimpleName());
//1.1
FileInputFormat.setInputPaths(job, INPUT_PATH);
//
job.setInputFormatClass(TextInputFormat.class);
//1.2 Mapper
job.setMapperClass(MyMapper.class);
//
job.setMapOutputKeyClass(NewK2.class);
job.setMapOutputValueClass(LongWritable.class);
//1.3
job.setPartitionerClass(HashPartitioner.class);
job.setNumReduceTasks(1);
//1.4 TODO 、
//1.5 TODO ( )
//2.2 reduce
job.setReducerClass(MyReducer.class);
//
job.setOutputKeyClass(LongWritable.class);
job.setOutputValueClass(LongWritable.class);
//2.3
FileOutputFormat.setOutputPath(job, new Path(OUT_PATH));
//
job.setOutputFormatClass(TextOutputFormat.class);
// JobTracker
job.waitForCompletion(true);
}
/**
* Mapper
* @author liuyazhuang
*
*/
static class MyMapper extends Mapper{
protected void map(LongWritable key, Text value, org.apache.hadoop.mapreduce.Mapper.Context context) throws java.io.IOException ,InterruptedException {
final String[] splited = value.toString().split("\t");
final NewK2 k2 = new NewK2(Long.parseLong(splited[0]), Long.parseLong(splited[1]));
final LongWritable v2 = new LongWritable(Long.parseLong(splited[1]));
context.write(k2, v2);
};
}
/**
* Reducer
* @author liuyazhuang
*
*/
static class MyReducer extends Reducer{
protected void reduce(NewK2 k2, java.lang.Iterable v2s, org.apache.hadoop.mapreduce.Reducer.Context context) throws java.io.IOException ,InterruptedException {
context.write(new LongWritable(k2.first), new LongWritable(k2.second));
};
}
/**
* : ?
* : v2 , k2 v2 , k2
* @author liuyazhuang
*/
static class NewK2 implements WritableComparable{
Long first;
Long second;
public NewK2(){}
public NewK2(long first, long second){
this.first = first;
this.second = second;
}
@Override
public void readFields(DataInput in) throws IOException {
this.first = in.readLong();
this.second = in.readLong();
}
@Override
public void write(DataOutput out) throws IOException {
out.writeLong(first);
out.writeLong(second);
}
/**
* k2 , .
* , ; ,
* @author liuyazhuang
*/
@Override
public int compareTo(NewK2 o) {
final long minus = this.first - o.first;
if(minus !=0){
return (int)minus;
}
return (int)(this.second - o.second);
}
@Override
public int hashCode() {
return this.first.hashCode()+this.second.hashCode();
}
@Override
public boolean equals(Object obj) {
if(!(obj instanceof NewK2)){
return false;
}
NewK2 oK2 = (NewK2)obj;
return (this.first==oK2.first)&&(this.second==oK2.second);
}
}
}
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