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名师互学网 > IT > 前沿技术 > 大数据 > 大数据系统

hadoop二次排序,自定义计数器

hadoop二次排序,自定义计数器

import org.apache.hadoop.io.WritableComparable;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;


public class SortWritable implements WritableComparable {

    private String first;
    private int second;


    
    @Override
    public int compareTo(SortWritable o) {
       int i = this.first.compareTo(o.first);
       if(i==0){
           int i1 = Integer.valueOf(this.second+"").compareTo(Integer.valueOf(o.second));
           return i1;
       }else{
           return i;
       }
    }

    
    @Override
    public void write(DataOutput out) throws IOException {
        out.writeUTF(this.first);
        out.writeInt(second);
    }

    
    @Override
    public void readFields(DataInput in) throws IOException {
        this.first=in.readUTF();
        this.second=in.readInt();
    }

    public String getFirst() {
        return first;
    }

    public void setFirst(String first) {
        this.first = first;
    }

    public int getSecond() {
        return second;
    }

    public void setSecond(int second) {
        this.second = second;
    }

    @Override
    public String toString() {
        return this.first+"t"+this.second;
    }
}

import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Counter;
import org.apache.hadoop.mapreduce.Mapper;

import java.io.IOException;

public class SortMap extends Mapper {
    @Override
    protected void map(LongWritable key, Text value, Mapper.Context context) throws IOException, InterruptedException {
        //定义计数器Map输入多少条
        Counter counter = context.getCounter("MR_COUNT", "MapRecordCounter");
        counter.increment(1L);

        String[] strings = value.toString().split("t");
        SortWritable sortWritable = new SortWritable();
        sortWritable.setFirst(strings[0]);
        sortWritable.setSecond(Integer.parseInt(strings[1]));
        context.write(sortWritable,NullWritable.get());
        System.out.println(sortWritable.toString());
    }
}

import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.mapreduce.Reducer;

import java.io.IOException;

public class SortReduce extends Reducer {
    @Override
    protected void reduce(SortWritable key, Iterable values, Reducer.Context context) throws IOException, InterruptedException {
        org.apache.hadoop.mapreduce.Counter counter = context.getCounter(Counter.REDUCE_INPUT_RECORDS);
        counter.increment(1L);
        for (NullWritable nullWritable:values) {
            context.write(key,NullWritable.get());
            org.apache.hadoop.mapreduce.Counter counter1 = context.getCounter(Counter.REDUCE_OUTPUT_RECORDS);
            counter1.increment(1L);
        }

    }

    public static enum Counter{
        REDUCE_INPUT_RECORDS, REDUCE_OUTPUT_RECORDS,
    }
}
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