💡 [Feature Request] Migrate from OkHttp to Feign

[yvasyliev]

Is your feature request related to a problem? Please describe.

I would like to be able to provide my own HTTP client to interact with Telegram Bots API. In fact, JDK 11 HttpClient is sufficient to displace OkHttp usage while allowing to get rid of Kotlin & third-party dependencies and supporting CompletableFuture natively.

Describe the solution you'd like

Feign is a declarative HTTP client that allows users to use whatever HTTP client implementation they want (JDK 11 HttpClient, OkHttp, Apache HC, etc.). I think Feign is the best candidate for API wrapper libraries like telegram-bots.

Describe alternatives you've considered

An alternative might be a custom HttpClient interface with default OkHttp implementation. However, I think this approach would be an overengineering since Feign already exists.

Additional context

Unlike OkHttp, Feign is a declarative client, meaning that complete API methods rework is required bringing severe breaking changes.

[Chase22]

While i do agree that this is a good idea, i do want to point out that the Lib already contains an abstraction: https://github.com/rubenlagus/TelegramBots/blob/master/telegrambots-client/src/main/java/org/telegram/telegrambots/client/AbstractTelegramClient.java. You might be able to implement this for your choosen client lib as a stepgap

[yvasyliev]

Thanks for pointing out @Chase22! I was looking into TelegramBotsLongPollingApplication.java and it seems that it's not using AbstractTelegramClient.

BTW I just found that Google HTTP Client does the same thing as Feign, but it's an imperative client. So, it might be "less painful" to migrate to Google client, in case if it's ever gonna happen.