Access from Java a Scala object that inherits from a generic Java base class

Question

Sorry for the wordy title :) Here is the Scala object:

object TokenPosition extends java.lang.ThreadLocal[Int]

And here is the Java code that uses it:

TokenPosition$.MODULE$.set(position);

Eclipse gives me the following warning:

Type safety: The method set(Object) belongs to the raw type ThreadLocal. References to generic type ThreadLocal<T> should be parameterized

What should I do? Or is this an inherent limitation of Generics and Java/Scala interop?

does the simpler TokenPosition.set( position ) not work? does it still warn? — Steve Waldman
– Steve Waldman, Commented Mar 1, 2015 at 12:30
@SteveWaldman No, Java access to Scala object fields is a bit more complicated :) — fredoverflow
– fredoverflow, Commented Mar 1, 2015 at 12:43
i thought recent versions of Scala offered pretty forwarding methods, see "Forwarding Methods" twitter.github.io/scala_school/java.html here. But apparently that's only with companion objects, and probably not for inherited members. You could try adding a class TokenPosition; for the forwarding and specialize, object TokenPosition extends java.lang.ThreadLocal[Int] { def set( i : Int ) : Unit = super.set(i); } — Steve Waldman
– Steve Waldman, Commented Mar 1, 2015 at 13:31

lpiepiora · Accepted Answer · 2015-02-28 14:24:06Z

1

Try changing Int to Integer, Int is like Java's int, and Integer is a wrapper, so it should help.

answered Feb 28, 2015 at 14:24

lpiepiora

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