SettableListenableFuture.setException(Throwable) doesn't work for Error [SPR-14298]

[spring-projects-issues]

Alexis Terrat opened SPR-14298 and commented

Hi,
I encountered a bug using a SettableListenableFuture.
When I call future.setException() with a Throwable that is not an Exception, it is set as a result instead. So, it raises a ClassCastException. See the samples below.

And sorry if this is a duplicate btw :)

sample 1 :

• code :
  SettableListenableFuture<String> future = new SettableListenableFuture<>();
  Consumer<String> printRes = res -> System.out.println("success " + res);
  Consumer<Throwable> printErr = err -> System.out.println("failure " + err);
  future.addCallback(printRes::accept, printErr::accept);
  future.setException(new Throwable("test"));

• expected output :
  failure java.lang.Throwable: test

• actual output :
  failure java.lang.ClassCastException: java.lang.Throwable cannot be cast to java.lang.String

sample 2 :

• code :
  SettableListenableFuture<Throwable> future = new SettableListenableFuture<>();
  Consumer<Throwable> printRes = res -> System.out.println("success " + res);
  Consumer<Throwable> printErr = err -> System.out.println("failure " + err);
  future.addCallback(printRes::accept, printErr::accept);
  future.setException(new Throwable("test"));

• expected output :
  failure java.lang.Throwable: test

• actual output :
  success java.lang.Throwable: test

---

Affects: 4.2.5

Referenced from: commits cc77588, a979885

Backported to: 4.2.7