concurrent and atomic map?

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Daisy - 02 Dec 2005 19:39 GMT

I'm confused by the concurrent map offering for Java 1.5. Ideally, I
would like to use primitive long keys in a
java.util.concurrent.ConcurrentHashMap. There is a constructor
ConcurrentHashMap(Map<? extends K,? extends V>t ). Is it possible to
use a primitive type as a key in ConcurrentHashMap?

Alternatively, I have used the gnu maps that allow primitives.

Thanks

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Oliver Wong - 02 Dec 2005 19:41 GMT

> I'm confused by the concurrent map offering for Java 1.5. Ideally, I
> would like to use primitive long keys in a
[quoted text clipped - 3 lines]
>
> Alternatively, I have used the gnu maps that allow primitives.

As far as I know, it's not possible. The keys of the map must be an
Object (or something which extends Object), and not a primitive. What you
can do is box your longs into Long objects. Java 1.5 will do this
automatically for you if you try to supply a primitive long.

- Oliver

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Roedy Green - 02 Dec 2005 20:20 GMT

>Is it possible to
>use a primitive type as a key in ConcurrentHashMap?

you can use Longs then use autoboxing unboxing.

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Canadian Mind Products, Roedy Green.
http://mindprod.com Java custom programming, consulting and coaching.

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concurrent and atomic map?

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