基于MapReduce的手机流量统计分析

1，代码

package mr;

import java.io.IOException;

import org.apache.commons.lang.StringUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.ArrayWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.Writable;
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;

/**
 * 使用ArrayWritable
 */
public class TrafficApp4 {

    public static void main(String[] args) throws Exception{
        Configuration conf = new Configuration();
        Job job = Job.getInstance(conf , TrafficApp4.class.getSimpleName());
        job.setJarByClass(TrafficApp4.class);

        FileInputFormat.setInputPaths(job, args[]);
        job.setMapperClass(TrafficMapper.class);
        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(LongArrayWritable.class);

        job.setReducerClass(TrafficReducer.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(LongArrayWritable.class);
        FileOutputFormat.setOutputPath(job, new Path(args[]));

        job.waitForCompletion(true);
    }

    public static class TrafficMapper extends Mapper<LongWritable, Text, Text, LongArrayWritable>{
        @Override
        protected void map(LongWritable key, Text value,
                Mapper<LongWritable, Text, Text, LongArrayWritable>.Context context)
                        throws IOException, InterruptedException {
            String line = value.toString();
            String[] splited = line.split("\t");
            String phonenumber = splited[];

            String upPackNum = splited[];
            String downPackNum = splited[];
            String upPayLoad = splited[];
            String downPayLoad = splited[];

            Text k2 = new Text(phonenumber);
            LongArrayWritable v2 = new LongArrayWritable(upPackNum, downPackNum, upPayLoad, downPayLoad);
            context.write(k2, v2);
        }
    }

    public static class TrafficReducer extends Reducer<Text, LongArrayWritable, Text, LongArrayWritable>{
        @Override
        protected void reduce(Text k2, Iterable<LongArrayWritable> v2s,
                Reducer<Text, LongArrayWritable, Text, LongArrayWritable>.Context context)
                        throws IOException, InterruptedException {

            long upPackNum = 0L;
            long downPackNum = 0L;
            long upPayLoad = 0L;
            long downPayLoad = 0L;
            for (LongArrayWritable v2 : v2s) {
                Writable[] values = v2.get();
                upPackNum += ((LongWritable)values[]).get();
                downPackNum += ((LongWritable)values[]).get();
                upPayLoad += ((LongWritable)values[]).get();
                downPayLoad += ((LongWritable)values[]).get();
            }

            LongArrayWritable v3 = new LongArrayWritable(upPackNum, downPackNum, upPayLoad, downPayLoad);
            context.write(k2, v3);
        }
    }

    public static class LongArrayWritable extends ArrayWritable{
        /**
         * 在调用的时候，首先调用该方法，然后调用set(Writable[])
         */
        public LongArrayWritable() {
            super(LongWritable.class);
        }
        /**
         * 直接调用该方法即可
         * @param values
         */
        public LongArrayWritable(LongWritable[] values) {
            super(LongWritable.class, values);
        }
        /**
         * 直接调用该方法即可
         * @param upPackNum
         * @param downPackNum
         * @param upPayLoad
         * @param downPayLoad
         */
        public LongArrayWritable(Long upPackNum, Long downPackNum, Long upPayLoad, Long downPayLoad) {
            super(LongWritable.class);
            LongWritable[] values = new LongWritable[];
            values[] = new LongWritable(upPackNum);
            values[] = new LongWritable(downPackNum);
            values[] = new LongWritable(upPayLoad);
            values[] = new LongWritable(downPayLoad);
            super.set(values);
        }
        /**
         * 直接调用该方法即可
         * @param upPackNum
         * @param downPackNum
         * @param upPayLoad
         * @param downPayLoad
         */
        public LongArrayWritable(String upPackNum, String downPackNum, String upPayLoad, String downPayLoad) {
            super(LongWritable.class);
            LongWritable[] values = new LongWritable[];
            values[] = new LongWritable(Long.parseLong(upPackNum));
            values[] = new LongWritable(Long.parseLong(downPackNum));
            values[] = new LongWritable(Long.parseLong(upPayLoad));
            values[] = new LongWritable(Long.parseLong(downPayLoad));
            super.set(values);
        }

        @Override
        public String toString() {
            String[] array =  super.toStrings();
            return StringUtils.join(array, "\t");
        }
    }

}

2，ArrayWritable的API

org.apache.hadoop.io
Class ArrayWritable

java.lang.Object
  

org.apache.hadoop.io.ArrayWritable

已实现的接口：

Writable

---

public class ArrayWritableextends Objectimplements Writable

A Writable for arrays containing instances of a class. The elements of this writable must all be instances of the same class. If this writable will be the input for a Reducer, you will need to create a subclass that sets the value to be of the proper type. For example: public class IntArrayWritable extends ArrayWritable { public IntArrayWritable() { super(IntWritable.class); } }

---

构造方法摘要

ArrayWritable(Class<? extends Writable> valueClass) 
           

ArrayWritable(Class<? extends Writable> valueClass, Writable[] values) 
           

ArrayWritable(String[] strings) 
           

方法摘要
Writable[]	get()
Class	getValueClass()
void	readFields(DataInput in)            Deserialize the fields of this object from in.
void	set(Writable[] values)
Object	toArray()
String[]	toStrings()
void	write(DataOutput out)            Serialize the fields of this object to out.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造方法详细信息

ArrayWritable

public ArrayWritable(Class<? extends Writable> valueClass)

---

ArrayWritable

public ArrayWritable(Class<? extends Writable> valueClass,
                     Writable[] values)

---

ArrayWritable

public ArrayWritable(String[] strings)

方法详细信息

getValueClass

public Class getValueClass()

---

toStrings

public String[] toStrings()

---

toArray

public Object toArray()

---

set

public void set(Writable[] values)

---

get

public Writable[] get()

---

readFields

public void readFields(DataInput in)
                throws IOException

Description copied from interface: Writable

Deserialize the fields of this object from in.

For efficiency, implementations should attempt to re-use storage in the existing object where possible.

Specified by:

readFields in interface Writable

Parameters:

in - DataInput to deseriablize this object from.

Throws:

IOException

---

write

public void write(DataOutput out)
           throws IOException

Description copied from interface: Writable

Serialize the fields of this object to out.

Specified by:

write in interface Writable

Parameters:

out - DataOuput to serialize this object into.

Throws:

IOException