CompletionStage：在异常块内返回CompletionStage

Question

如果发生异常，有没有办法返回新的CompletionStage？

exceptionally的API，似乎不允许您这样做。有办法解决这个问题吗？

基本上我想为flatMap案例thenCompose（exceptionally）做

public CompletionStage<String> cleanupTask() {
  //DO something long running
}

public CompletionStage<String> workThatCanFail() {
  //Some long running task that may fail
}

public void action() {

CompletionStage<String> work = 
    workThatCanFail()
    .exceptionally(throwable -> cleanupTask());

}