Calling Scala Method from Java - Set<Object> or Set<Long>? -


java

set<long> set = new hashset<long>(); set.add(100); long x = 2; foo(x, set);

scala

def foo(a: long, b: java.util.set[long])

error:

could not parse error message:           required: long,set<object>       found: long,set<long>        reason: actual argument set<long> cannot converted        set<object> method  invocation conversion

then, modified java code resolve compile-time error.

set<object> set = new hashset<object>();

however, resolution of compile-time error came @ expense of type safety. how can resolve above error?

edit

after @som-snytt resolved issues here, ran problem. don't think it's same question since , in linked question, using, in scala, foo(long, java.util.set[long]) worked when calling (from java) scalaobject.foo(long, set[long])

the types wrong. type of set in java code java.util.set[java.lang.long], while type in scala java.util.set[scala.long]. scala.long type treated primitive long in java, when not erased, , java.lang.object when erased (as uncovered).

so either change scala's type java's type match. it's unfortunate scala.long erases java.lang.object, necessary.


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