用java,scala,python三种语言实现spark rdd的treeReduce算子

Java实现：

import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.function.Function2;

public class TreeReduceExample {
    public static void main(String[] args) {
        SparkConf conf = new SparkConf().setAppName("TreeReduceExample").setMaster("local");
        JavaSparkContext sc = new JavaSparkContext(conf);

        JavaRDD<Integer> rdd = sc.parallelize(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));

        Integer result = rdd.treeReduce(new Function2<Integer, Integer, Integer>() {
            public Integer call(Integer a, Integer b) throws Exception {
                return a + b;
            }
        });

        System.out.println("Result: " + result);

        sc.close();
    }
}

Scala实现：

import org.apache.spark.{SparkConf, SparkContext}

object TreeReduceExample {
  def main(args: Array[String]) {
    val conf = new SparkConf().setAppName("TreeReduceExample").setMaster("local")
    val sc = new SparkContext(conf)

    val rdd = sc.parallelize(Seq(1, 2, 3, 4, 5, 6, 7, 8, 9, 10))

    val result = rdd.treeReduce((a: Int, b: Int) => a + b)

    println("Result: " + result)

    sc.stop()
  }
}

Python实现：

from pyspark import SparkConf, SparkContext

conf = SparkConf().setAppName("TreeReduceExample").setMaster("local")
sc = SparkContext(conf=conf)

rdd = sc.parallelize([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])

result = rdd.treeReduce(lambda a, b: a + b)

print("Result: " + str(result))

sc.stop()