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

Posted 2020-08-23 大数据和人工智能躺过的坑

 

 

　　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;

public class RunJob {

// 小明 老王 如花 林志玲
// 老王 小明 凤姐 排序在FoFSort.java
// 如花 小明 李刚 凤姐
// 林志玲 小明 李刚 凤姐 郭美美 分组在FoFGroup.java
// 李刚 如花 凤姐 林志玲
// 郭美美 凤姐 林志玲
// 凤姐 如花 老王 林志玲 郭美美


public static void main(String[] args) {
Configuration config =new Configuration();
// config.set("fs.defaultFS", "hdfs://HadoopMaster:9000");
// config.set("yarn.resourcemanager.hostname", "HadoopMaster");
// config.set("mapred.jar", "C:\\\\Users\\\\Administrator\\\\Desktop\\\\wc.jar");
// config.set("mapreduce.input.keyvaluelinerecordreader.key.value.separator", ",");//默认分隔符是制表符"\\t"，这里自定义，如","
if(run1(config)){
run2(config);//设置两个run，即两个mr。
}
}

public static void run2(Configuration config) {
try {
FileSystem fs =FileSystem.get(config);
Job job =Job.getInstance(config);
job.setJarByClass(RunJob.class);

job.setJobName("fof2");

job.setMapperClass(SortMapper.class);
job.setReducerClass(SortReducer.class);
job.setSortComparatorClass(FoFSort.class);
job.setGroupingComparatorClass(FoFGroup.class);
job.setMapOutputKeyClass(User.class);
job.setMapOutputValueClass(User.class);

job.setInputFormatClass(KeyValueTextInputFormat.class);

// //设置MR执行的输入文件
// FileInputFormat.addInputPath(job, new Path("hdfs://HadoopMaster:9000/f1"));
//
// //该目录表示MR执行之后的结果数据所在目录，必须不能存在
// Path outputPath=new Path("hdfs://HadoopMaster:9000/out/f2");

//设置MR执行的输入文件
FileInputFormat.addInputPath(job, new Path("./out/f1"));

//该目录表示MR执行之后的结果数据所在目录，必须不能存在
Path outputPath=new Path("./out/f2");


if(fs.exists(outputPath)){
fs.delete(outputPath, true);
}
FileOutputFormat.setOutputPath(job, outputPath);

boolean f =job.waitForCompletion(true);
if(f){
System.out.println("job 成功执行");
}

} catch (Exception e) {
e.printStackTrace();
}
}

public static boolean run1(Configuration config) {
try {
FileSystem fs =FileSystem.get(config);
Job job =Job.getInstance(config);
job.setJarByClass(RunJob.class);
job.setJobName("friend");
job.setMapperClass(FofMapper.class);
job.setReducerClass(FofReducer.class);
job.setMapOutputKeyClass(Fof.class);
job.setMapOutputValueClass(IntWritable.class);

job.setInputFormatClass(KeyValueTextInputFormat.class);

// FileInputFormat.addInputPath(job, new Path("hdfs://HadoopMaster:9000/friend/friend.txt"));//下有friend.txt
//
// Path outpath =new Path("hdfs://HadoopMaster:9000/out/f1");

FileInputFormat.addInputPath(job, new Path("./data/friend/friend.txt"));//下有friend.txt

Path outpath =new Path("./out/f1");



if(fs.exists(outpath)){
fs.delete(outpath, true);
}
FileOutputFormat.setOutputPath(job, outpath);

boolean f= job.waitForCompletion(true);
return f;
} catch (Exception e) {
e.printStackTrace();
}
return false;
}

static class FofMapper extends Mapper<Text, Text, Fof, IntWritable>{
protected void map(Text key, Text value,
Context context)
throws IOException, InterruptedException {
String user =key.toString();
String[] friends =StringUtils.split(value.toString(), \'\\t\');
for (int i = 0; i < friends.length; i++) {
String f1 = friends[i];
Fof ofof =new Fof(user, f1);
context.write(ofof, new IntWritable(0));
for (int j = i+1; j < friends.length; j++) {
String f2 = friends[j];
Fof fof =new Fof(f1, f2);
context.write(fof, new IntWritable(1));
}
}
}
}

static class FofReducer extends Reducer<Fof, IntWritable, Fof, IntWritable>{
protected void reduce(Fof arg0, Iterable<IntWritable> arg1,
Context arg2)
throws IOException, InterruptedException {
int sum =0;
boolean f =true;
for(IntWritable i: arg1){
if(i.get()==0){
f=false;
break;
}else{
sum=sum+i.get();
}
}
if(f){
arg2.write(arg0, new IntWritable(sum));
}
}
}

static class SortMapper extends Mapper<Text, Text, User, User>{

protected void map(Text key, Text value,
Context context)
throws IOException, InterruptedException {
String[] args=StringUtils.split(value.toString(),\'\\t\');
String other=args[0];
int friendsCount =Integer.parseInt(args[1]);

context.write(new User(key.toString(),friendsCount), new User(other,friendsCount));
context.write(new User(other,friendsCount), new User(key.toString(),friendsCount));
}
}

static class SortReducer extends Reducer<User, User, Text, Text>{
protected void reduce(User arg0, Iterable<User> arg1,
Context arg2)
throws IOException, InterruptedException {
String user =arg0.getUname();
StringBuffer sb =new StringBuffer();
for(User u: arg1 ){
sb.append(u.getUname()+":"+u.getFriendsCount());
sb.append(",");
}
arg2.write(new Text(user), new Text(sb.toString()));
}
}