MapReduce - A - 分组 - Comparator

题目：
求每个通信商的上行、下行、总流量 (输出：通信商 上行 下行 总的)

思路：
通过手机号的前三位区分通信运营商
按照运营商分组后，在每个Reduce里计算各运营商总和即可

代码：

//分组比较器

package Comparator02;

import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.io.WritableComparator;

public class MyComparator extends WritableComparator {
    //将要重新定义的分组的key的类型传进来
    public MyComparator(){
        super(RecordWritable.class, true);
    }

    public int compare(WritableComparable a, WritableComparable b){
        RecordWritable a1 = (RecordWritable)a;
        RecordWritable b1 = (RecordWritable)b;
        return a1.getProduct().compareTo(b1.getProduct());
    }
}

//实体类

package Comparator02;

import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;

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

public class RecordWritable implements WritableComparable {
    private String product;//运营商

    public void write(DataOutput dataOutput) throws IOException {
        dataOutput.writeUTF(this.product);

    }

    public void readFields(DataInput dataInput) throws IOException {
        this.product = dataInput.readUTF();

    }

    public int compareTo(Object o) {
        RecordWritable b = (RecordWritable) o;
        return this.product.compareTo(b.getProduct());
    }

    @Override
    public String toString() {
        return "RecordWritable{" +
                "product=" + product +
                '}';
    }

    public String getProduct() {
        return product;
    }

    public void setProduct(String product) {
        this.product = product;
    }


}

//MapReduce

package Comparator02;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
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 java.io.IOException;

public class MainDemo {
    public static  void main(String[] args){
        try{
            Configuration conf = new Configuration();

            Job job = Job.getInstance(conf, "Partitioner02-MainDemo");

            job.setJarByClass(MainDemo.class);

            job.setMapperClass(MyMapper.class);
            job.setMapOutputKeyClass(RecordWritable.class);
            job.setMapOutputValueClass(LongWritable.class);

            job.setReducerClass(MyReducer.class);
            job.setOutputKeyClass(Text.class);
            job.setOutputValueClass(LongWritable.class);

            //设置自定义分组
            job.setGroupingComparatorClass(MyComparator.class);

            FileInputFormat.addInputPath(job, new Path("C:/Users/Administrator/Desktop/Data/input/flow.log"));
            FileOutputFormat.setOutputPath(job, new Path("C:/Users/Administrator/Desktop/Data/output/02/00"));

            int success = job.waitForCompletion(true) ? 0: 1;

            System.exit(success);
        }
        catch (Exception e){
            e.printStackTrace();
        }
    }
    //自定义的Mapper类
    public static class MyMapper extends Mapper<Object, Text, RecordWritable, LongWritable>{
        RecordWritable k = new RecordWritable();
        LongWritable v = new LongWritable();
        @Override
        protected void map(Object key, Text value, Context context) throws IOException, InterruptedException {
            String tov = "";
            String row = value.toString();
            String[] words = row.split("\t");
            int len = words.length;
            v.set(Integer.parseInt(words[len-3]) + Integer.parseInt(words[len-2]));
            String[] st = words[1].split(" ");
            String st2 = st[0].substring(0,3);
            if(st2.matches("(139)|(138)|(137)|(136)|(135)|(134)|(159)|(158)|(157)|(150)|(151)|(152)|(147)|(188)|(187)|(182)|(183)|(184)|(178)")){
                k.setProduct("移动");
            }
            else if(st2.matches("(130)|(131)|(132)|(156)|(155)|(186)|(185)|(145)|(176)")){
                k.setProduct("联通");
            }
            else if(st2.matches("(133)|(153)|(189)|(180)|(181)|(177)|(173)")){
                k.setProduct("电信");
            }
            else {
                k.setProduct("其它");
            }
            context.write(k, v);
        }
    }
    //自定义的Reducer类
    public static class MyReducer extends Reducer<RecordWritable, LongWritable, Text, LongWritable>{
        public Text k = new Text();
        public LongWritable v = new LongWritable();
        @Override
        protected void reduce(RecordWritable key, Iterable<LongWritable> values, Context context) throws IOException, InterruptedException {
            long sum = 0;
            for(LongWritable lw: values){
                sum += lw.get();
            }
            k.set(key.getProduct());
            v.set(sum);
            context.write(k, v);
        }
    }
}