Hadoop MapReduce编程 API入门系列之FOF（Fund of Fund）（二十三）

　　不多说，直接上代码。

代码

package zhouls.bigdata.myMapReduce.friend;

import org.apache.hadoop.io.Text;

public class Fof extends Text{//自定义Fof，表示f1和f2关系

public Fof(){//无参构造
super();
}

public Fof(String a,String b){//有参构造
super(getFof(a, b));
}

public static String getFof(String a,String b){
int r =a.compareTo(b);
if(r<0){
return a+"\t"+b;
}else{
return b+"\t"+a;
}
}
}

package zhouls.bigdata.myMapReduce.friend;

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

import org.apache.hadoop.io.WritableComparable;

public class User implements WritableComparable<User>{
//WritableComparable,实现这个方法，要多很多
//readFields是读入，write是写出
private String uname;
private int friendsCount;

public String getUname() {
return uname;
}
public void setUname(String uname) {
this.uname = uname;
}
public int getFriendsCount() {
return friendsCount;
}
public void setFriendsCount(int friendsCount) {
this.friendsCount = friendsCount;
}//这一大段的get和set，可以右键，source，产生get和set，自动生成。

public User() {//无参构造

}

public User(String uname,int friendsCount){//有参构造
this.uname=uname;
this.friendsCount=friendsCount;
}

public void write(DataOutput out) throws IOException { //序列化
out.writeUTF(uname);
out.writeInt(friendsCount);
}

public void readFields(DataInput in) throws IOException {//反序列化
this.uname=in.readUTF();
this.friendsCount=in.readInt();
}

public int compareTo(User o) {//核心
int result = this.uname.compareTo(o.getUname());
if(result==0){
return Integer.compare(this.friendsCount, o.getFriendsCount());
}
return result;
}

}

package zhouls.bigdata.myMapReduce.friend;

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

public class FoFSort extends WritableComparator{

public FoFSort() {//把自定义的User，传进了
super(User.class,true);
}

public int compare(WritableComparable a, WritableComparable b) {//排序核心
User u1 =(User) a;
User u2=(User) b;

int result =u1.getUname().compareTo(u2.getUname());
if(result==0){
return -Integer.compare(u1.getFriendsCount(), u2.getFriendsCount());
}
return result;
}
}

package zhouls.bigdata.myMapReduce.friend;

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

public class FoFGroup extends WritableComparator{

public FoFGroup() {//把自定义的User，传进了
super(User.class,true);
}

public int compare(WritableComparable a, WritableComparable b) {//分组核心
User u1 =(User) a;
User u2=(User) b;

return u1.getUname().compareTo(u2.getUname());
}
}

package zhouls.bigdata.myMapReduce.friend;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.DoubleWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.NullWritable;
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.input.KeyValueTextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.StringUtils;