Combine two Futures into one, without changing value type?

[googl...@schildbach.de]

 I have two futures with the same value T which I want to combine into one. Futures.allAsList() seems to do what I want but it changes the value of the combined future from T to List<T>. Is there something similar that doesn't change the value type?

See https://github.com/bitcoinj/bitcoinj/blob/master/core/src/main/java/org/bitcoinj/core/Peer.java#L163

[amertum]

You can find how on scala doc : http://docs.scala-lang.org/overviews/core/futures.html#functional-composition-and-for-comprehensions

and other here : http://buransky.com/scala/scala-for-comprehension-with-concurrently-running-futures/

It depends of what result you want to return.

[Chris Povirk]

For now, you can call transform() on the result of allAsList().

Once Guava 20 is out (in the next few months), you can do something like:

Futures.whenAllSucceed(a, b).call(-> doSomething(a, b));

[googl...@schildbach.de]

Thanks for the hint. What type is transform() a method of? I've been looking in ListenableFuture and all subtypes but could not find anything.

[Chris Povirk]

transform(), along with other ListenableFuture utilities, are available in Futures.java.