WordCount对比spark——java

 

使用spark编写的WordCount！

package com.test

import org.apache.spark.{SparkConf, SparkContext}

object Spark_Test {
  def main(args: Array[String]): Unit = {
    val sparkConf = new SparkConf().setMaster("local").setAppName("job_name")
    val sc = new SparkContext(sparkConf)

    val file = sc.textFile("E:\\aa.txt")
    val flatMap = file.flatMap{line => line.split(" ")}
    val map = flatMap.map(world =>(world,1))
    val byKey = map.reduceByKey(_+_).map(tuple => (tuple._2,tuple._1))//使用touple把key value 位置转换（按value排序）
　　 val sortvalue = byKey.sortByKey(true).map(tuple => (tuple._2,tuple._1))//false 倒序 调换位置，使其单词在前，sum在后
　 　sortvalue.foreach(x => println(x))

  }
}

  使用java编写的WordCount！

package spark;

import java.util.Arrays;
import java.util.Iterator;

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 com.sun.org.apache.bcel.internal.generic.LMUL;

import scala.Tuple2;


public final class JavaWorldCount {
    public static void main(String[] args) {
        SparkConf sparkConf = new SparkConf().setMaster("local").setAppName("job_name");
        JavaSparkContext sc = new JavaSparkContext(sparkConf);
        
        JavaRDD<String> textFile = sc.textFile("E:/aa.txt");
        JavaRDD<String> flatMap = textFile.flatMap(new FlatMapFunction<String, String>() {

            private static final long serialVersionUID = 1L;

            @Override
            public Iterator<String> call(String line) throws Exception {
                return Arrays.asList(line.split(" ")).iterator();
            }
        });
        
        JavaPairRDD<String,Integer> mapToPair = flatMap.mapToPair(new PairFunction<String, String, Integer>() {

            private static final long serialVersionUID = 1L;

            @Override
            public Tuple2<String, Integer> call(String word) throws Exception {
                return new Tuple2<String, Integer>(word, 1);
            }
        });
        
        //三个int 前两个位计算单词数量 _+_ = INT 最后一个是和
        JavaPairRDD<String,Integer> reduceByKey = mapToPair.reduceByKey(new Function2<Integer, Integer, Integer>() {
            
            private static final long serialVersionUID = 1L;

            @Override
            public Integer call(Integer v1, Integer v2) throws Exception {
                return v1+v2;
            }
        });
        
        JavaPairRDD<Integer,String> mapToPair2 = reduceByKey.mapToPair(new PairFunction<Tuple2<String,Integer>, Integer, String>() {

            private static final long serialVersionUID = 1L;

            @Override
            public Tuple2<Integer, String> call(Tuple2<String, Integer> tuple)
                    throws Exception {
                return new Tuple2<Integer, String>(tuple._2,tuple._1);
            }
        });
        
        JavaPairRDD<String,Integer> sortByKey = mapToPair2.sortByKey(false).mapToPair(new PairFunction<Tuple2<Integer,String>, String, Integer>() {

            private static final long serialVersionUID = 1L;

            @Override
            public Tuple2<String, Integer> call(Tuple2<Integer, String> tuple)
                    throws Exception {
                return new Tuple2<String, Integer>(tuple._2,tuple._1);
            }
        });
        
        sortByKey.foreach(new VoidFunction<Tuple2<String,Integer>>() {
            
            private static final long serialVersionUID = 1L;

            @Override
            public void call(Tuple2<String, Integer> tuple) throws Exception {
                System.out.println(tuple);
            }
        });
        
        
        
        
    }
}