Retrofit Slower response time in real android devices when compared to emulator and web

Question

I am making a restful API call from Android device to populate a list view .

I have used swagger codegen to generate my retrofit client .

Dagger 2 for dependency injection

Device : Asus Zenfone 5

I have tried to make call from postman, web and also in emulator (genymotion) it is much faster compared to a real device.

And interesting thing is that every time when I restart my phone for two to three request the response time is normal and after that getting slower.

I read some blog regarding gzip compression in okHTTP and try to implement that but no effect.

It would be really helpful if someone can help me to figure out the issue.

Answer 1

In retrofit, it does following work:

1. Build up the Retrofit class.
2. Impl the Interface with DynamicProxy
3. Parse and create the Http request accourding to the annotations.
4. Send and receive HTTP(socket) IOs with OkHttp in ThreadPool(In Android, Network can't be done on main thread).
5. Deserialize your Http body with some lib (eg. gson).
6. update UI in callback.

In your phone, I think 1,2,3 won't be necessary, they can even be done on main thread or cached. In my device (Qcom615, 2Gram), it will take less than one ms.

So you need to debug with your network.

fix problem one by one:

4. Is your server use HTTPS or no-cacahe or no-gzip? Logging your data and tell your server's partner, they can give you some advice.
5. try faster lib for converters.
6. improve your view's code(eg. void redraw/relayout, void a long-time job in main thread).