java-tutorials/apache-spark/src/main/java/com/baeldung/WordCount.java

41 lines
1.5 KiB
Java

package com.baeldung;
import java.util.Arrays;
import java.util.List;
import java.util.regex.Pattern;
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.*;
import org.apache.spark.api.java.function.Function2;
import org.apache.spark.api.java.function.PairFunction;
import scala.Tuple2;
public class WordCount {
private static final Pattern SPACE = Pattern.compile(" ");
public static void main(String[] args) throws Exception {
if (args.length < 1) {
System.err.println("Usage: JavaWordCount <file>");
System.exit(1);
}
SparkConf sparkConf = new SparkConf().setAppName("JavaWordCount")
.setMaster("local");
JavaSparkContext ctx = new JavaSparkContext(sparkConf);
JavaRDD<String> lines = ctx.textFile(args[0], 1);
JavaRDD<String> words = lines.flatMap(s -> Arrays.asList(SPACE.split(s)).iterator());
JavaPairRDD<String, Integer> wordAsTuple = words.mapToPair(word -> new Tuple2<>(word, 1));
JavaPairRDD<String, Integer> wordWithCount = wordAsTuple.reduceByKey((Integer i1, Integer i2)->i1 + i2);
List<Tuple2<String, Integer>> output = wordWithCount.collect();
for (Tuple2<?, ?> tuple : output) {
System.out.println(tuple._1() + ": " + tuple._2());
}
ctx.stop();
}
}