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Newsgroups: comp.lang.java.programmer
Date: Tue, 26 Aug 2014 12:18:47 -0700 (PDT)
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Subject: Re: Exception Handling in Asynchronous Java Code
From: dario.crivelli@lightstreamer.com
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Xref: csiph.com comp.lang.java.programmer:29861

Hi Sebastian, my colleague Valerio informed me of your suggestion.
I acknowledge that CompletableFuture offers a management of exceptions that is more powerful than the native support provided by the Java syntax.
However, it views exceptions as some sort of showstoppers, not as special conditions each of which may deserve a different treatment.
In fact, it does not allow you to selectively handling some types of exceptions while keeping others for further steps:
you can only handle all types of possible exceptions in the same step, perhaps to log an error at the end of the processing.

This seems to be by design; I don't know the story behind, but I wonder why there is a method
    CompletableFuture<T> exceptionally(Function<Throwable,? extends T> fn);
but not something like
    CompletableFuture<T> exceptionally(Function<Throwable,CompletionStage<T>> fn);
Am I missing something?