Retrofit如何设置baseUrl？

Question

I want to set the BaseUrl in Retrofit to change dynamically between stage and live because i have an app that has stage and live version. So i made a spinner and the user can select either he wants. But the problem is that after the user select the flavor he wants and then wants to change again it doens't work because the baseUrl is not changing like it should be.

I have this class where is defined the API_URL but it's not working:

@Singleton
class SingleUrlApi {
    companion object{
        public var API_URL_STAGE = BuildConfig.STAGE
    }
}

and then i have another function that uses this API_URL_STAGE

 override fun getUrl(shopUrl: ShopUrl, vararg args: String): String {
        return when (shopUrl) {
            ShopUrl.API_BASE -> if (SingleUrlApi.API_URL_STAGE) {
                context.localizedContext(localeManager.getCurrentLocale()).getString(R.string.base_url_stage)
            } else {
                context.localizedContext(localeManager.getCurrentLocale()).getString(R.string.base_url_live)
            }
            ShopUrl.WEB_BASE -> if (SingleUrlApi.API_URL_STAGE) {
                context.localizedContext(localeManager.getCurrentLocale()).getString(R.string.base_web_url_stage)
            } else {
                context.localizedContext(localeManager.getCurrentLocale()).getString(R.string.base_web_url_live)
            }

Answer 1

You can use OkHttp along with Retrofit. Then, you can use an OkHttpInterceptor to change the URL of the request

public final class HostSelectionInterceptor implements Interceptor {

  @Override public okhttp3.Response intercept(Chain chain) throws IOException {
    Request request = chain.request();
    String host = //logic to fetch the new URL
    if (host != null) {
      HttpUrl newUrl = request.url().newBuilder()
          .host(host)
          .build();
      request = request.newBuilder()
          .url(newUrl)
          .build();
    }
    return chain.proceed(request);
  }
}

Answer 2

An easy and effective way is to use this library: RetrofitUrlManager