[Feature Request] Http proxy support in version 7

[deko2369]

Feature Request

I want to use MessagingApiClient with HTTP proxy in version 7.

In version 6, LineMessagingClient is available via proxy using the following code:

// This is v6 code.
OkHttpClient.Builder okHttpClientBuilder = new OkHttpClient.Builder();
Authenticator proxyAuthenticator =
        (route, response) -> response
                .request()
                .newBuilder()
                .header("Proxy-Authorization", "Bearer <token>")
                .build();
okHttpClientBuilder
    .proxy(
        new Proxy(
            Proxy.Type.HTTP,
            new InetSocketAddress("proxy.example.com", 8080)
        )
    )
    .proxyAuthenticator(proxyAuthenticator);

RetryableLineMessagingClient
    .builder("token")
    .okHttpClientBuilder(okHttpClientBuilder, true)
    .build();

[tokuhirom]

Ah, since version 7, SDK developers decide to hide the implementation detail of the HTTP client library. As a result, there's no hook point to set proxy configuration in version 7.
So, we need to add the interface to configure proxy...

[tokuhirom]

And so, this document is not correct in version 7. https://github.com/line/line-bot-sdk-java#how-do-i-use-a-proxy-server

[deko2369]

Thank you for your reply.
Do you have any plan to add proxy interface to MessagingApiClient?

[tokuhirom]

Maybe the interface should be like this:

        api = MessagingApiClient.builder("MY_OWN_TOKEN")
            .apiEndPoint(URI.create(wireMockServer.baseUrl()))
            .proxy(
                new Proxy(
                    Proxy.Type.HTTP,
                    new InetSocketAddress("proxy.example.com", 8080)
                )
            )
            .build();

(Proxy object is java.net.Proxy

[tokuhirom]

I proposed PR

[deko2369]

Looks good to me!

In addition, proxy server may have authentication (using Proxy-Authorization HTTP header), the client needs to have an interface to set Authenticator instance.
https://square.github.io/okhttp/4.x/okhttp/okhttp3/-ok-http-client/-builder/proxy-authenticator/

[deko2369]

Thanks!