09、高级编程之基于排序机制的wordcount程序

package sparkcore.java;

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 scala.Tuple2;

/**

 * 排序的wordcount程序：根据单词出现的次数进行排序

 */

public class SortWordCount {

    public static void main(String[] )

    val ) }

    val wordCounts = pairs.reduceByKey(_ + _)

    val countWords = wordCounts.map(wordCount => (wordCount._2, wordCount._1))

    val sortedCountWords = countWords.sortByKey(false)

    val sortedWordCounts = sortedCountWords.map(sortedCountWord => (sortedCountWord._2, sortedCountWord._1))

    sortedWordCounts.foreach(sortedWordCount => println(sortedWordCount._1 + " : " + sortedWordCount._2))

  }

}