> On 13 Nov 2018, at 02:35, Weijun Wang <weijun.w...@oracle.com> wrote:
>
> I'm scanning a file and downloading links inside:
>
> lines.flapMap(x -> Stream.ofNullable(findURIFrom(x)))
> .map(l -> download(c, l))
> .forEach(f -> f.join());
>
> CompletableFuture<HttpResponse<Path>> download(HttpClient c, URI link) {
> return c.sendAsync(HttpRequest.newBuilder(link).build(),
> HttpResponse.BodyHandlers.ofFile(Path.of(link.getPath())));
> }
>
> However, it seems the download is one by one and not parallel.
1. CompletableFuture.join waits until the result (or exception) is available
2. I guess the "lines" stream is created from Files.lines(Path)? If so, then
* this method does not read all lines into a {@code List}, but instead
* populates lazily as the stream is consumed
> I can only collect the jobs into a list and then call join() on
> CompletableFuture.allOf(list). Is there a simpler way?
This seems to be a correct way of waiting until all the links have been
downloaded (possibly in parallel, depending on the Executor you use for
HttpClient) or an error occurred.
