Adding header to all request with Retrofit 2

Question

Retrofit 2\'s documentation says:

Headers that need to be added to every request can be specified using an OkHttp interceptor.

I

Answer 1

RetrofitHelper library written in kotlin, will let you make API calls, using a few lines of code.

Add headers in your application class like this :

class Application : Application() {

    override fun onCreate() {
    super.onCreate()

        retrofitClient = RetrofitClient.instance
                    //api url
                .setBaseUrl("https://reqres.in/")
                    //you can set multiple urls
        //                .setUrl("example","http://ngrok.io/api/")
                    //set timeouts
                .setConnectionTimeout(4)
                .setReadingTimeout(15)
                    //enable cache
                .enableCaching(this)
                    //add Headers
                .addHeader("Content-Type", "application/json")
                .addHeader("client", "android")
                .addHeader("language", Locale.getDefault().language)
                .addHeader("os", android.os.Build.VERSION.RELEASE)
            }

        companion object {
        lateinit var retrofitClient: RetrofitClient

        }
    }  

And then make your call:

retrofitClient.Get()
            //set path
            .setPath("api/users/2")
            //set url params Key-Value or HashMap
            .setUrlParams("KEY","Value")
            // you can add header here
            .addHeaders("key","value")
            .setResponseHandler(GetResponseModel::class.java,
                object : ResponseHandler() {
                    override fun onSuccess(response: Response) {
                        super.onSuccess(response)
                        //handle response
                    }
                }).run(this)

For more information see the documentation