On Mon, 7 Jul 2025 10:41:58 GMT, Volkan Yazici <vyaz...@openjdk.org> wrote:
>> Adds a new `ofFileChannel(FileChannel channel, long offset, long length)`
>> method to `java.net.HttpRequest.BodyPublishers` to provide an `HttpClient`
>> publisher to upload a certain region of a file. The new publisher does not
>> modify the state of the passed `FileChannel`, streams the file channel bytes
>> as it publishes (i.e., avoids reading the entire file into the memory), and
>> can be leveraged to implement sliced uploads. As noted in the Javadoc:
>>
>>> The file channel will not be closed upon completion. The caller is
>>> expected to manage the life cycle of the channel, and close it
>>> appropriately when not needed anymore.
>>
>> ### Implementation notes
>>
>> - `FileChannel` is preferred over `{Readable,Seekable}ByteChannel`, since
>> the latter does not provide a positional read without modifying the state of
>> the `FileChannel`, which is necessary to use a single `FileChannel` instance
>> to implement sliced uploads.
>> - `ofFileChannel(FileChannel,long,long)` is preferred over
>> `ofPath(Path,long,long)` to avoid overloading the maximum file descriptor
>> limit of the platform.
>
> Volkan Yazici has updated the pull request incrementally with one additional
> commit since the last revision:
>
> Improve docs on `IndexOutOfBoundsException` thrown
>
> Co-authored-by: Daniel Fuchs <67001856+df...@users.noreply.github.com>
src/java.net.http/share/classes/java/net/http/HttpRequest.java line 747:
> 745: public static BodyPublisher ofFileChannel(FileChannel channel,
> long offset, long length) {
> 746: Objects.requireNonNull(channel, "channel");
> 747: return new RequestPublishers.FileChannelPublisher(channel,
> offset, length);
Hello Volkan, I see that the constructor of `FileChannelPublisher` attempts to
determine the file size of the channel and if an `IOException` is thrown then
it gets propagated as `UncheckedIOException`. I think an alternate approach
and perhaps a better one would be to specify in this new method's documentation
that the `FileChannel`'s size will be first determined by this method to verify
that the given `offset` and the `length` are within bounds of that size. That
then allows us to add a throws clause to this method which we merely propagate
from the call of `FileChannel.size()`.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/26155#discussion_r2213322140
