Win7 Eclipse 搭建spark java1.8(lambda)环境：WordCount helloworld例子 马克-to-win @ 马克java社区：lambda表达式是java8给我们带来的一个重量的新特性，借用lambda表达式可以让我们的程序设计更加简洁。 package com; 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.VoidFunction; import scala.Tuple2; import java.util.Arrays; import java.util.List; public class WordCountLambda { public static void main(String[] args) { SparkConf conf = new SparkConf().setAppName("WordCountLambda马克-to-win @ 马克java社区：").setMaster("local"); JavaSparkContext sc = new JavaSparkContext(conf); JavaRDD<String> lines = sc.textFile("E://temp//input//friend.txt"); JavaRDD<String> words = lines.flatMap(line -> Arrays.asList(line.split(" "))); JavaPairRDD<String, Integer> wordAndOne = words.mapToPair(word -> new Tuple2<>(word, 1)); JavaPairRDD<String, Integer> results = wordAndOne.reduceByKey((x, y) -> x + y); /* 下面一句也能工作。*/ // reduced.saveAsTextFile("E://temp//input//friend1.txt"); /*word:o1abc count:4 word:45 count:1 word:77 count:1*/ results.foreach(new VoidFunction<Tuple2<String,Integer>>() { public void call(Tuple2<String, Integer> tuple) throws Exception { System.out.println("word:" + tuple._1 + " count:" + tuple._2); } }); /*resultsPair is (o1abc,4) resultsPair is (45,1) resultsPair is (77,1)*/ List<Tuple2<String,Integer>> resultsPairs = results.collect(); for (Tuple2<String, Integer> resultsPair : resultsPairs) {
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