자바 판 spark 의 map 연산 자 사용

import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.Function;
import org.apache.spark.api.java.function.VoidFunction;

import java.util.Arrays;
import java.util.List;

public class Test02 {
    public static void main(String[] args) {
        map();
    }
    /**
     * transformation    
     * @param args
     */

        /**
         * map    ,            2
         */
        public static void map(){
            //  SparkConf
            SparkConf conf = new SparkConf().setAppName("map").setMaster("local");
            //  javaSparkContext
            JavaSparkContext sc = new JavaSparkContext(conf);
            //    
            List numbers = Arrays.asList(1, 2, 3, 4, 5);
            //     ,    RDD
            JavaRDD numberRDD = sc.parallelize(numbers);

            //  map  ,           2
            //map  ,        RDD,      
            // java ,map        Function  
            //   function  ,            ,      ,         
            //              RDD

            JavaRDD rdd = numberRDD.map(new Function() {
                @Override
                public Integer call(Integer v1) throws Exception {
                    return v1 * 2;
                }
            });
            rdd.foreach(new VoidFunction() {
                @Override
                public void call(Integer t) throws Exception {
                    System.out.println(t);
                }
            });

            //    
            sc.close();


        }

}