How do I convert java.util.HashSet[java.lang.Long] to Scala Set[Long]

Question

I'm using:

import scala.collection.JavaConverters._
import scala.collection.Set

This works:

val a: java.util.HashSet[java.lang.Long] =  javaFunction(...)
val b: Set[java.lang.Long] = a.asScala.toSet

but what I want is a Set[Long], not a Set[java.lang.Long]. When I try this:

val a: java.util.HashSet[java.lang.Long] =  javaFunction(...)
val b: Set[Long] = a.asScala.toSet

I get: Expression of type scala.collection.immutable.Set[java.lang.Long] doesn't conform to expected type scala.collection.Set[Long].

Why is this and how do I get a Set[Long]?

Jean Logeart · Accepted Answer · 2018-04-24 20:00:37Z

6

Simply:

import scala.collection.JavaConverters._
val b: Set[Long] = a.asScala.map(Long2long).toSet

answered Apr 24, 2018 at 20:00

Jean Logeart

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