Java Spark算子：union

import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import java.util.Arrays;
import java.util.List;

/**
 * union() 算子：
 * 取两个RDD的并集,不去重,会增加partition(分区)的数量。
 *
 */
public class UnionDemo {
    public static void main(String[] args) {

        SparkConf conf = new SparkConf().setMaster("local").setAppName("spark");
        JavaSparkContext sc  = new JavaSparkContext(conf);
        List<String> list1 = Arrays.asList("i","love","u");
        List<String> list2 = Arrays.asList("soryy","maybe");

        //创建一个2分区的RDD
        JavaRDD<String> list1Rdd = sc.parallelize(list1,2);
        //创建一个1分区的RDD
        JavaRDD<String> list2Rdd = sc.parallelize(list2);

        //union算子，求并集。result会有三个分区。
        JavaRDD<String> result = list1Rdd.union(list2Rdd);

        //转化成list输出
        System.out.println(result.collect());
    }
}