Futures with onCompletion callback

[igor-petruk]

Does lettuce support specifying callbacks on completion of operations? Java Futures are not good enough, even though the operation is async, getting the value is synchronous, blocking. Using Java futures has all kinds of issues when desiging completely async applications and performing async computation composition

For example of better futures please see Scala futures, Guava ListenableFuture or Java 8 CompletableFuture, even custom callback is better then old Java Future

[sdeleuze]

I would really like have completableFuture support in lettuce!