Spark在Yarn上运行Wordcount程序

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 scala.Tuple2;

import java.util.Arrays;
import java.util.List;
import java.util.regex.Pattern;

public final class JavaWordCount {


    private static final Pattern SPACE = Pattern.compile(" ");
    public static void main(String[] args) {
       if(args.length<1){
           System.err.print("Usage:JavaWordCount<file>");
           System.exit(1);
       }

        SparkConf sparkConf = new SparkConf().setAppName("JavaWordCount");
        JavaSparkContext ctx = new JavaSparkContext(sparkConf);
        JavaRDD<String> lines = ctx.textFile(args[0],1);
        System.out.println(System.getenv("SPARK_HOME"));
        JavaRDD<String> words = lines.flatMap(new FlatMapFunction<String, String>() {
            @Override
            public Iterable<String> call(String s) throws Exception {
               return Arrays.asList(SPACE.split(s));
            }
        });

        JavaPairRDD<String,Integer> ones = words.mapToPair(new PairFunction<String, String, Integer>() {
            @Override
            public Tuple2<String, Integer> call(String s) throws Exception {
                return new Tuple2<String, Integer>(s,1);
            }
        });

        JavaPairRDD<String,Integer> counts = ones.reduceByKey(new Function2<Integer, Integer, Integer>() {
            @Override
            public Integer call(Integer i1, Integer i2) throws Exception {
                return i1+i2;
            }
        });

        List<Tuple2<String, Integer>> output = counts.collect();
        for (Tuple2<?, ?> tuple : output) {
               System.out.println(tuple._1() + ": " + tuple._2());
        }
        ctx.stop();
    }
}