编写一个简单的程序，实现以下功能:统计文本文件中出现的单词的个数

import java.util.Arrays;
import java.util.regex.Pattern;
import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.sql.SparkSession;
import scala.Tuple2;
public class JAVAWORDCOUNT {
static Pattern SPACE=Pattern.compile(" ");
  public static void main(String[] args) {
if(args.length<1) {
  System.out.println("error");
  System.exit(1);
}
  SparkSession spark=SparkSession.builder().
    master("local").appName("name").getOrCreate();
  JavaRDD<String> lines=spark.read().textFile(args[0]).javaRDD();
  JavaRDD<String> words=lines.flatMap(f->Arrays.asList(SPACE.split(f)).iterator());
  JavaPairRDD<String,Integer> ones=
    words.mapToPair(f->new Tuple2<String,Integer>(f,1));
  JavaPairRDD<String,Integer> counts=ones.reduceByKey((x,y)->(x+y));
  counts.foreach(f->System.out.println(f));
  spark.stop();
}
  }