如何从Java中的Java List创建scala.collection.immutable.Seq？ [英] How to create a scala.collection.immutable.Seq from a Java List in Java?

问题描述

我正在尝试让Akka进入我的Java项目，并且我在Scala上使用Seq类型的小问题。我能够将我的ActorRef的Java List转换为scala.collection.Seq，但我尝试使用的Akka API需要一个scala.collection.immutable.Seq。如何制作？

I'm trying to get Akka going in my Java project, and I'm hung up on a small issue with the Seq type(s) from Scala. I'm able to convert my Java List of ActorRef into a scala.collection.Seq, but the Akka API I'm trying to use requires a scala.collection.immutable.Seq. How can I make one?

代码：

static class Router extends UntypedLoadBalancer {
    private final InfiniteIterator<ActorRef> workers;

    public Router(List<ActorRef> workers) {
        Seq workerSeq = asScalaBuffer(workers);

        // how to get from the scala.collection.Seq above to the instance of
        // scala.collection.immutable.Seq required by CyclicIterator below?
        this.workers = new CyclicIterator<ActorRef>();
    }

    public InfiniteIterator<ActorRef> seq() {
        return workers;
    }
}

推荐答案

你可以使用 scala.collection.JavaConversions.asScalaBuffer 将Java 列表转换为Scala 缓冲区，其中包含 toList 方法，而Scala 列表为 collection.immutable.Seq 。

You can use scala.collection.JavaConversions.asScalaBuffer to convert the Java List to a Scala Buffer, which has a toList method, and a Scala List is a collection.immutable.Seq.

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