1. 需求

统计每一个手机号耗费的总上行流量、下行流量、总流量

（1）输入数据

（2）输入数据格式：

（3）期望输出数据格式

　　2．编写MapReduce程序 

package com.atguigu.mapreduce.flowsum;

import java.io.DataInput;

import java.io.DataOutput;

import java.io.IOException;

import org.apache.hadoop.io.Writable;


// 1 实现writable接口

public class FlowBean implements Writable{


private long upFlow;

private long downFlow;

private long sumFlow;

//2 反序列化时，需要反射调用空参构造函数，所以必须有

public FlowBean() {

super();

}


public FlowBean(long upFlow, long downFlow) {

super();

this.upFlow = upFlow;

this.downFlow = downFlow;

this.sumFlow = upFlow + downFlow;

}

//3 写序列化方法

@Override

public void write(DataOutput out) throws IOException {

out.writeLong(upFlow);

out.writeLong(downFlow);

out.writeLong(sumFlow);

}

//4 反序列化方法

//5 反序列化方法读顺序必须和写序列化方法的写顺序必须一致

@Override

public void readFields(DataInput in) throws IOException {

this.upFlow = in.readLong();

this.downFlow = in.readLong();

this.sumFlow = in.readLong();

}


// 6 编写toString方法，方便后续打印到文本

@Override

public String toString() {

return upFlow + "\t" + downFlow + "\t" + sumFlow;

}


public long getUpFlow() {

return upFlow;

}


public void setUpFlow(long upFlow) {

this.upFlow = upFlow;

}


public long getDownFlow() {

return downFlow;

}


public void setDownFlow(long downFlow) {

this.downFlow = downFlow;

}


public long getSumFlow() {

return sumFlow;

}


public void setSumFlow(long sumFlow) {

this.sumFlow = sumFlow;

}

} 

　　（2）编写Mapper类

 package com.atguigu.mapreduce.flowsum;

import java.io.IOException;

import org.apache.hadoop.io.LongWritable;

import org.apache.hadoop.io.Text;

import org.apache.hadoop.mapreduce.Mapper;


public class FlowCountMapper extends Mapper<LongWritable, Text, Text, FlowBean>{

FlowBean v = new FlowBean();

Text k = new Text();

@Override

protected void map(LongWritable key, Text value, Context context)	throws IOException, InterruptedException {

// 1 获取一行

String line = value.toString();

// 2 切割字段

String[] fields = line.split("\t");

// 3 封装对象

// 取出手机号码

String phoneNum = fields[1];


// 取出上行流量和下行流量

long upFlow = Long.parseLong(fields[fields.length - 3]);

long downFlow = Long.parseLong(fields[fields.length - 2]);


k.set(phoneNum);

v.set(downFlow, upFlow);

// 4 写出

context.write(k, v);

}

}

 　　（3）编写Reducer类

package com.atguigu.mapreduce.flowsum;

import java.io.IOException;

import org.apache.hadoop.io.Text;

import org.apache.hadoop.mapreduce.Reducer;


public class FlowCountReducer extends Reducer<Text, FlowBean, Text, FlowBean> {


@Override

protected void reduce(Text key, Iterable<FlowBean> values, Context context)throws IOException, InterruptedException {


long sum_upFlow = 0;

long sum_downFlow = 0;


// 1 遍历所用bean，将其中的上行流量，下行流量分别累加

for (FlowBean flowBean : values) {

sum_upFlow += flowBean.getUpFlow();

sum_downFlow += flowBean.getDownFlow();

}


// 2 封装对象

FlowBean resultBean = new FlowBean(sum_upFlow, sum_downFlow);

// 3 写出

context.write(key, resultBean);

}

} 

 　　（4）编写Driver驱动类

package com.atguigu.mapreduce.flowsum;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.fs.Path;

import org.apache.hadoop.io.Text;

import org.apache.hadoop.mapreduce.Job;

import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;

import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;


public class FlowsumDriver {


public static void main(String[] args) throws IllegalArgumentException, IOException, ClassNotFoundException, InterruptedException {

// 输入输出路径需要根据自己电脑上实际的输入输出路径设置

args = new String[] { "e:/input/inputflow", "e:/output1" };


// 1 获取配置信息，或者job对象实例

Configuration configuration = new Configuration();

Job job = Job.getInstance(configuration);


// 6 指定本程序的jar包所在的本地路径

job.setJarByClass(FlowsumDriver.class);


// 2 指定本业务job要使用的mapper/Reducer业务类

job.setMapperClass(FlowCountMapper.class);

job.setReducerClass(FlowCountReducer.class);


// 3 指定mapper输出数据的kv类型

job.setMapOutputKeyClass(Text.class);

job.setMapOutputValueClass(FlowBean.class);


// 4 指定最终输出的数据的kv类型

job.setOutputKeyClass(Text.class);

job.setOutputValueClass(FlowBean.class);

// 5 指定job的输入原始文件所在目录

FileInputFormat.setInputPaths(job, new Path(args[0]));

FileOutputFormat.setOutputPath(job, new Path(args[1]));


// 7 将job中配置的相关参数，以及job所用的java类所在的jar包， 提交给yarn去运行

boolean result = job.waitForCompletion(true);

System.exit(result ? 0 : 1);

}

}