Can a terminal operation (e.g. forEach) rethrow checked exceptions?

Question

I have a method that deletes some files:

void deepDelete(Path root) {
    Files.walk(root)
            .filter(p -> !Files.isDirectory(p))
            .forEach(p -> { try { Files.delete(p); }
                            catch (IOException e) { /* LOG */ }
            });
}

The try/catch block reduces the readability of the operation, especially vs. using a method reference:

void deepDelete(Path root) throws IOException {
    Files.walk(root)
            .filter(p -> !Files.isDirectory(p))
            .forEach(Files::delete); //does not compile
}

Unfortunately that code does not compile.

Is there a way to apply an action that throws checked exceptions in a terminal operation and simply "rethrow" any exceptions?

I understand that I could write a wrapper that transforms the checked exception into an unchecked exception but I would rather stick to methods in the JDK if possible.

Answer 1

As far as I can tell: no. I use this techempower article as my java8 guide, and it's pretty explicit (see the section headed "Exception transparency").

Answer 2

If you declare this method:

@SuppressWarnings("unchecked")
static <T extends Throwable> RuntimeException sneakyThrow(Throwable t) throws T {
    throw (T)t;
}

Then you can do:

try {
    Files.delete(p);
} catch (IOException e) {
    throw sneakyThrow(e);
}

This bypasses the checked exception rules and throws the raw IOException without wrapping, although you still have to catch it & rethrow. I'm not saying this is a good idea, but it's an idea.