hadoop的自定义排序

package com.qq;
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;

public class SortApp {
/*    static final String INPUT_PATH = "hdfs://cloud4:9000/input";
    static final String OUT_PATH = "hdfs://cloud4:9000/out";*/
    public static void main(String[] args) throws Exception{
         Configuration conf = 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);
        }
        */
        Job job = Job.getInstance(conf);
        job.setJarByClass(SortApp.class);
        job.setMapperClass(MyMapper.class);
        job.setMapOutputKeyClass(NewK2.class);
        job.setMapOutputValueClass(LongWritable.class);
        FileInputFormat.setInputPaths(job,new Path(args[0]));
       //    job.setInputFormatClass(TextInputFormat.class);
        //job.setPartitionerClass(HashPartitioner.class);
        job.setReducerClass(MyReducer.class);
        job.setOutputKeyClass(LongWritable.class);
        job.setOutputValueClass(LongWritable.class);
        job.setNumReduceTasks(1);
        FileOutputFormat.setOutputPath(job,new Path(args[1]));
        job.waitForCompletion(true);
    }
    
    static class MyMapper extends Mapper<LongWritable, Text, NewK2, LongWritable>{
        protected void map(LongWritable key, Text value, Context context) throws java.io.IOException ,InterruptedException {
            final String[] splited = value.toString().split(",");
            final NewK2 k2 = new NewK2(Long.parseLong(splited[1]), Long.parseLong(splited[2]));
            final LongWritable v2 = new LongWritable(Long.parseLong(splited[2]));
            context.write(k2, v2);
        };
    }
    
    static class MyReducer extends Reducer<NewK2, LongWritable, LongWritable, LongWritable>{
        protected void reduce(NewK2 k2, java.lang.Iterable<LongWritable> v2s, Context context) throws java.io.IOException ,InterruptedException {
            context.write(new LongWritable(k2.first), new LongWritable(k2.second));
        };
    }
    
    static class  NewK2 implements WritableComparable<NewK2>{
        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);
        }

        
        @Override
        public int compareTo(NewK2 o) {
            final long minus =  this.first - o.first; //第一列不同时,第一列升序   第一列相同的时候第二列升序
            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);
        }
    }
    
}