Java 中用于 Spark 的 Scala Seq？

Question

我need to use SparkContext instead of JavaSparkContext for the accumulableCollection (if you don't agree check out the linked question请回答！）

澄清问题：SparkContext 在 Java 中可用，但需要 Scala 序列。如何让它快乐 -- 在 Java?

我有这个代码来做一个简单的 jsc.parallelize 我正在使用 JavaSparkContext, but SparkContext wants a Scala collection. I thought here I was building a Scala Range and converting it to a Java list, not sure how to get that core Range to be a Scala Seq, which is what the parallelize from SparkContext is asking for。

    // The JavaSparkContext way, was trying to get around MAXINT limit, not the issue here
    // setup bogus Lists of size M and N for parallelize
    //List<Integer> rangeM = rangeClosed(startM, endM).boxed().collect(Collectors.toList());
    //List<Integer> rangeN = rangeClosed(startN, endN).boxed().collect(Collectors.toList());

接下来是金钱线，我如何在 Java 中创建一个 Scala Seq 来并行化？

    // these lists above need to be scala objects now that we switched to SparkContext
    scala.collection.Seq<Integer> rangeMscala = scala.collection.immutable.List(startM to endM);

    // setup sparkConf and create SparkContext
    ... SparkConf setup
    SparkContext jsc = new SparkContext(sparkConf);

    RDD<Integer> dataSetMscala = jsc.parallelize(rangeMscala);

Answer 1

你应该这样使用它：

scala.collection.immutable.Range rangeMscala = 
  scala.collection.immutable.Range$.MODULE$.apply(1, 10);

SparkContext sc = new SparkContext();

RDD dataSetMscala = 
  sc.parallelize(rangeMscala, 3, scala.reflect.ClassTag$.MODULE$.Object());

希望对您有所帮助！此致

Java 中用于 Spark 的 Scala Seq？

Scala Seq for Spark in Java?

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apache-spark