mapreduce | 自定义Partition分区（案例2）

1.需求

统计每个手机号消费总金额，按照消费金额降序排序，最终联通、电信、移动分别写入不同的文件。

130、131、132（联通） 133（电信） 135、136、137、138、139 （移动）

手机号,消费记录

13512345678,50

13512345678,90

13122345678,10

13122345678,110

13212345678,10

13212345678,90

13912345378,10

13912345378,90

13612345678,50

13612345678,55

13312345378,65

13312345378,90

2.将数据上传到hdfs

3.Idea代码

MyPartition

package demo8;

import demo5.DescIntWritable;

import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Partitioner;

public class MyPartition extends Partitioner<DescIntWritable, Text> {

    @Override
    public int getPartition(DescIntWritable descIntWritable, Text text, int numPartitions) {
        String textStr = text.toString();
        boolean arr1 = textStr.startsWith("130") || textStr.startsWith("131") || textStr.startsWith("132");
        boolean arr2=textStr.startsWith("133");
        if(arr1){
            return 0;
        }else if(arr2){
            return 1;
        }
        return 2;
    }
}

PhoneBillJob

package demo8;

import demo5.DescIntWritable;

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.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;

import java.io.IOException;

public class PhoneBillJob {
    public static void main(String[] args) throws IOException, InterruptedException, ClassNotFoundException {
        Configuration conf = new Configuration();
        conf.set("fs.defaultFS","hdfs://hadoop10:8020");

        Job job = Job.getInstance(conf);
        job.setJarByClass(PhoneBillJob.class);

        job.setInputFormatClass(TextInputFormat.class);
        job.setOutputFormatClass(TextOutputFormat.class);

        TextInputFormat.addInputPath(job,new Path("/phtest/phone.txt"));
        TextOutputFormat.setOutputPath(job,new Path("/phtest/out"));

        job.setMapperClass(PhoneBillMapper.class);
        job.setReducerClass(PhoneBillReducer.class);
        //map输出的键与值类型
        job.setMapOutputKeyClass(DescIntWritable.class);
        job.setMapOutputValueClass(Text.class);
        //reducer输出的键与值类型
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(DescIntWritable.class);

        //设置reduceTask的个数
        job.setNumReduceTasks(3);
        //设置自定义分区
        job.setPartitionerClass(MyPartition.class);

        boolean b = job.waitForCompletion(true);
        System.out.println(b);


    }

    static class PhoneBillMapper extends Mapper<LongWritable, Text,DescIntWritable,Text> {

        @Override
        protected void map(LongWritable key, Text value,Context context) throws IOException, InterruptedException {
            String[] arr = value.toString().split(",");
            context.write(new DescIntWritable(Integer.parseInt(arr[1])),new Text(arr[0]));
        }
    }
    static class PhoneBillReducer extends Reducer<DescIntWritable,Text,Text,DescIntWritable> {
        @Override
        protected void reduce(DescIntWritable key, Iterable<Text> values, Context context) throws IOException, InterruptedException {
            for (Text value : values) {
                context.write(value, key);
            }
        }
    }}

4.在hdfs上查看结果

就一直往前走吧，别回头~