java wordcount

知者何南 · 2023-7-8 01:05:49

import com.google.common.base.Splitter;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.FlatMapFunction;
import org.apache.spark.api.java.function.Function2;
import org.apache.spark.api.java.function.PairFunction;
import org.apache.spark.api.java.function.VoidFunction;
import scala.Tuple2;
import java.util.Arrays;
import java.util.Iterator;
public class WordCount {
public static void main(String[] args) {
SparkConf sparkConf = new SparkConf().setAppName("WordCount").setMaster("local");
JavaSparkContext sc = new JavaSparkContext(sparkConf);
JavaRDD<String> lines = sc.textFile("file:/Users/zhudechao/gitee/bigdata/xzdream_spark/input/a.txt");
JavaRDD<String> words = lines.flatMap(new FlatMapFunction<String, String>() {
@Override
public Iterator<String> call(String line) throws Exception {
return Arrays.asList(line.split(" ")).iterator();
}
});
JavaPairRDD<String,Integer> pairRDD = words.mapToPair(new PairFunction<String, String, Integer>() {
@Override
public Tuple2<String, Integer> call(String word) throws Exception {
return new Tuple2<String, Integer>(word,1);
}
});
JavaPairRDD<String,Integer> wordCounts = pairRDD.reduceByKey(new Function2<Integer, Integer, Integer>() {
@Override
public Integer call(Integer v1, Integer v2) throws Exception {
return v1 + v2;
}
});
wordCounts.foreach(new VoidFunction<Tuple2<String, Integer>>() {
@Override
public void call(Tuple2<String, Integer> wordcount) throws Exception {
System.out.println(wordcount._1 + ":"+wordcount._2);
}
});
}
}

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package com.huawei.mapreduce.wordcount;
import java.io.IOException;
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.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
public class WordCountApp {
public static class MyMapper extends Mapper<LongWritable, Text, Text, LongWritable>{
@Override
protected void map(LongWritable key, Text value, Mapper<LongWritable, Text, Text, LongWritable>.Context context) throws IOException, InterruptedException {
String line = value.toString();
String[] splited = line.split("\t");
for (String word : splited) {
Text k2 = new Text(word);
LongWritable v2 = new LongWritable(1);
context.write(k2, v2);
}
}
}
public static class MyReducer extends Reducer<Text, LongWritable, Text, LongWritable>{
@Override
protected void reduce(Text k2, Iterable<LongWritable> v2s,
Reducer<Text, LongWritable, Text, LongWritable>.Context context) throws IOException, InterruptedException {
long count = 0L;
for (LongWritable times : v2s) {
count += times.get();
}
LongWritable v3 = new LongWritable(count);
context.write(k2, v3);
}
}
public static void main(String[] args) throws Exception{
Configuration conf = new Configuration();
Job job = Job.getInstance(conf , WordCountApp.class.getSimpleName());
//必须指定
job.setJarByClass(WordCountApp.class);
//指定本业务job要使用的Mapper业务类
job.setMapperClass(MyMapper.class);
//指定mapper输出数据的<k2,v2>的类型
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(LongWritable.class);
//指定本业务job要使用的Reducer业务类
job.setReducerClass(MyReducer.class);
//指定reducer输出数据的<k3,v3>的类型
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(LongWritable.class);
//输入数据来自哪里
FileInputFormat.setInputPaths(job, new Path(args[0]));
//输出数据写到哪里
FileOutputFormat.setOutputPath(job, new Path(args[1]));
//true表示将运行进度等信息及时输出给用户
boolean res = job.waitForCompletion(true);
System.exit(res?0:1);
}
}

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tar -zxvf jdk-8u341-linux-x64.tar.gz
wget https://hcip-materials.obs.cn-north-4.myhuaweicloud.com/jdk-8u341-linux-x64.tar.gz
scp ~/eclipse-workspace/HDFSAPI/target/HDFSAPI-jar-with-dependencies.jar root@xxx.xxx.xxx.xxx:/root
ssh root@xxx.xxx.xxx.xxx
yarn jar HDFSAPI-jar-with-dependencies.jar com.huawei.hdfs.IsFile
yarn jar HDFSAPI-jar-with-dependencies.jar com.huawei.hdfs.CreateFile1
yarn jar HDFSAPI-jar-with-dependencies.jar com.huawei.hdfs.IsFile
yarn jar HDFSAPI-jar-with-dependencies.jar com.huawei.hdfs.CreateFile1
yarn jar HDFSAPI-jar-with-dependencies.jar com.huawei.hdfs.CreateFile2
yarn jar HDFSAPI-jar-with-dependencies.jar com.huawei.hdfs.ScanFile /user/test/hdfs/file10.txt
yarn jar HDFSAPI-jar-with-dependencies.jar com.huawei.hdfs.ScanFile /user/test/hdfs/file11.txt
yarn jar HDFSAPI-jar-with-dependencies.jar com.huawei.hdfs.DeleteFile /user/test/hdfs/file10.txt
yarn jar HDFSAPI-jar-with-dependencies.jar com.huawei.hdfs.IsFile
yarn jar MRAPI-jar-with-dependencies.jar com.huawei.mapreduce.wordcount.WordCountApp /user/user1/MR_data /user/user1/MR_out
hdfs dfs -mkdir /user/user1
hdfs dfs -put MR_data /user/user1/
hdfs dfs -ls /user/user1/MR_out/
hdfs dfs -cat /user/user1/MR_out/part-r-00000
hdfs dfs -mkdir -p /user/user1/MR/input
hdfs dfs -mkdir -p /user/user1/MR/output
hdfs dfs -put mrsort.txt /user/user1/MR/input
hdfs dfs -ls /user/user1/MR/output
hdfs dfs -cat /user/user1/MR/output/part-r-00000
hdfs dfs -cat /user/user1/MR/output/part-r-00001
hdfs dfs -cat /user/user1/MR/output/part-r-00002

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java wordcount

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