Implement a utility class to save large downloads to a file

[sbordet]

HttpClient could benefit of a utility class that saves the download bytes to a file, akin to:

curl <url> -o file.bin

Perhaps call it PathResponseListener.

Beware that FileChannel.write(ByteBuffer) returns the number of bytes written, that can be less than the bytes in the buffer, see also #630.

[stale]

This issue has been automatically marked as stale because it has been a full year without activity. It will be closed if no further activity occurs. Thank you for your contributions.

[sbordet]

Would still be nice to have.

[stale]

This issue has been automatically marked as stale because it has been a full year without activity. It will be closed if no further activity occurs. Thank you for your contributions.

[github-actions]

This issue has been automatically marked as stale because it has been a
full year without activity. It will be closed if no further activity occurs.
Thank you for your contributions.

[github-actions]

This issue has been automatically marked as stale because it has been a
full year without activity. It will be closed if no further activity occurs.
Thank you for your contributions.

[github-actions]

This issue has been automatically marked as stale because it has been a
full year without activity. It will be closed if no further activity occurs.
Thank you for your contributions.

[sbordet]

@arsenalzp are you interested in implementing this one?

[arsenalzp]

@arsenalzp are you interested in implementing this one?

Hello,
Let's manage with it!

[sbordet]

@arsenalzp this is how I would like to use it:

// Async mode.
httpClient.newRequest(host, port)
  .send(new PathResponseListener(Path.of("/tmp/file.bin"));

// CompletableFuture mode.
var request = httpClient.newRequest(host, port);
CompletableFuture<Path> completable = PathResponseListener.write(request, Path.of("/tmp/file.bin"));

PathResponseListener should implement CompleteListener and one of the content listeners, perhaps ContentListener is enough.

Start with simple test cases: a test that writes 0 bytes, one that writes 1 MiB and one that writes more than 1 GiB.
Make sure at the end of the test the files are deleted.
Then write test cases for failures: for example a Path that does not exist, a Path that exist but it is not writable, a download that is interrupted by the server (the server writes some content, then closes the connection), etc.

Let me know if you need more guidance.