Use HttpConnectionProvider mutate method

[yangbongsoo]

Motivation

I want to make new ConnectionProvider using defaultHttpClient.configuration().connectionProvider().mutate() operation.
However I can't use mutate() method.

  return new ReactorClientHttpConnector(reactorResourceFactory, defaultHttpClient -> {
    // builder value is always null.
    Builder builder = defaultHttpClient.configuration().connectionProvider().mutate();

  }
}

Because HttpConnectionProvider(defaultHttpClient type is HttpConnectionProvider) don't override mutate() method and default mutate() method return null.

@FunctionalInterface
public interface ConnectionProvider extends Disposable {
	@Nullable
	default Builder mutate() {
		return null;
	}
}

Desired solution

private ReactorClientHttpConnector customize(maxIdleTimeoutMillis, maxLifeTimeoutMillis) {
  return new ReactorClientHttpConnector(reactorResourceFactory, defaultHttpClient -> {
    ConnectionProvider provider = defaultHttpClient.configuration().connectionProvider()
        .mutate()
        .name("provider")
        .maxIdleTime(Duration.ofMillis(maxIdleTimeoutMillis))
        .maxLifeTime(Duration.ofMillis(maxLifeTimeoutMillis))
        .build();

    HttpClient httpClient = HttpClient.create(provider)
  }
}

I made PR #2463

Considered alternatives

I have a question. Violetagg told me that defaultHttpClient.configuration().connectionProvider() should return the original ConnectionProvider.

So I made below test code. I think that configuredConnectionProvider.http1ConnectionProvider return the original ConnectionProvider. Isn't it? Please tell me if I'm mistaken.

@Test
void configuredConnectionProviderShouldReturnTheOriginalConnectionProvider() {
	ConnectionProvider provider = ConnectionProvider.create("provider");
	try {
		HttpClient client = HttpClient.create(provider);
		HttpConnectionProvider configuredConnectionProvider =
				(HttpConnectionProvider) client.configuration().connectionProvider();
		assertThat(provider.getClass().getName())
				.isEqualTo(configuredConnectionProvider.http1ConnectionProvider.getClass().getName());
	}
	finally {
		provider.disposeLater()
				.block(Duration.ofSeconds(5));
	}
}