[java_http] send request body

[alex-james-dev]

This is a PR for the java_http GSoC '23 project 🌞.
Relevant tracking issue: #957.

Purpose

The purpose of this PR is to make the package:java_http client send the request body to the server.
We are now passing another two package:http_client_conformance_tests 🎉:

1. testIsolate()
2. testRequestBody()

The testRequestBody() tests were initially failing because we can't send a StreamedRequest object between isolates.

Reviewers

@HosseinYousefi
@natebosch

---

• I’ve reviewed the contributor guide and applied the relevant portions to this PR.

Contribution guidelines:

• See our contributor guide for general expectations for PRs.
• Larger or significant changes should be discussed in an issue before creating a PR.
• Contributions to our repos should follow the Dart style guide and use dart format.
• Most changes should add an entry to the changelog and may need to rev the pubspec package version.
• Changes to packages require corresponding tests.

Note that many Dart repos have a weekly cadence for reviewing PRs - please allow for some latency before initial review feedback.

[HosseinYousefi]

LGTM

[natebosch]

[optional] Is there any value in minimizing the uses of callMethodWithArgs and avoiding interop calls in a loop?

(untested suggestion)

Suggested change

	httpUrlConnection.setDoOutput(true);
	final outputStream = httpUrlConnection.getOutputStream();
	requestBody.forEach(outputStream.write);
	outputStream
	httpUrlConnection.setDoOutput(true);
	final outputStream = httpUrlConnection.getOutputStream();
	final bodyArray = JArray(jbyte.type, requestBody.length)
	..setRange(0, requestBody.length, requestBody);
	outputStream
	..write1(bodyArray)

[alex-james-dev]

Sounds like a good idea to me!

I've pushed a commit with the suggestions and the tests were all passing locally.

Thank you 😄

[alex-james-dev]

I've been learning about extension methods recently, could we add an extension method to Uint8List?

extension on Uint8List {
  JArray<jbyte> toJArray() =>
      JArray(jbyte.type, length)..setRange(0, length, this);
}

Then, the code would go from:

    final bodyArray = JArray(jbyte.type, requestBody.length)
      ..setRange(0, requestBody.length, requestBody);

    httpUrlConnection.getOutputStream()
      ..write1(bodyArray)
      ..flush()
      ..close();

to:

    httpUrlConnection.getOutputStream()
      ..write1(requestBody.toJArray())
      ..flush()
      ..close();

My intuition is that adding an extension method to Uint8List is unnecessary at the moment. But if it becomes a common occurence to convert Uint8List to JArray<jbyte> in java_http then it would be a nice idea to add an extension method.

[natebosch]

could we add an extension method to Uint8List?

This extension method does look like a good idea.

[alex-james-dev]

Awesome! Let's go for the extension method toJArray() on Uint8List.

[natebosch]

LGTM as is, or with the discussed extension method toJArray().

[alex-james-dev]

Hey @natebosch,

I've pushed a commit which adds the extension method toJArray() on Uint8List.

I'm new to extension methods and I'm not sure where the best place to put the extension method is.
I ended up taking inspiration from package:checks and created an extensions directory.

But I'm open to ideas about where to put the extension method.

Thank you!

[natebosch]

I'm open to ideas about where to put the extension method.

For something very short like this which is used in 1 place, I usually start with a private extension locally within the library. A "utils" or "extensions" directory or library like you chose here is also great.

It's a pretty low-impact decision in this case which is why I approved without commenting. Since you're looking for input on best practices my recommendation would be a private local extension for this one.

extension on Uint8List {

For example:

https://github.com/dart-lang/async/blob/b65622afa33c5bfc574ae6b34d5a61f18a98f83c/lib/src/cancelable_operation.dart#L560

[alex-james-dev]

Hey @natebosch,

Thanks for explaining when to use an unnamed extension and where to store named extensions, I'll definitely remember that for the future 🧠.

I've pushed a commit to make the change to a private extension, I think it looks better. The example you linked was very helpful.

I appreciate your help!