Android中Retrofit请求无响应无错误，enqueue未进入回调问题排查

Let's break down the key issues stopping your Retrofit call from hitting onResponse or onFailure, and fix them step by step:

1. Your OkHttpClient Timeout Settings Aren't Being Applied #

You're building the OkHttpClient before setting your timeout values — that means the client passed to Retrofit has no timeout config at all, and if the request hangs, it might never trigger a callback.

Here's the corrected order for configuring your client:

public void getCheapestFromToSpain() {
    OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
    // Set timeouts FIRST, then build the client
    httpClient.connectTimeout(5, TimeUnit.MINUTES)
            .writeTimeout(5, TimeUnit.MINUTES)
            .readTimeout(5, TimeUnit.MINUTES);

    Retrofit retrofit = new Retrofit.Builder()
            .baseUrl(urlGetCheapest)
            .addConverterFactory(GsonConverterFactory.create())
            .client(httpClient.build()) // Use the already-configured builder
            .build();

    // ... rest of your code (date formatting, creating the call, etc.)
}

2. Base URL and @GET Path Conflict #

Retrofit has strict rules for combining base URLs and endpoint paths:

• Your base URL must end with a trailing / (yours does: https://services-api.ryanair.com/farfnd/3/)
• Your @GET path must not start with a leading / — otherwise, Retrofit will ignore the base URL's path and jump straight to the domain.

Your current @GET("/oneWayFares") is making a request to https://services-api.ryanair.com/oneWayFares instead of the correct https://services-api.ryanair.com/farfnd/3/oneWayFares. Fix the Controller interface:

public interface Controller {
    @GET("oneWayFares") // Remove the leading slash
    Call<GetCheapestResponseType> getCheapest(
            @Query("departureAirportIataCode") String departureAirportIataCode,
            @Query("outboundDepartureDateFrom") String outboundDepartureDateFrom,
            @Query("outboundDepartureDateTo") String outboundDepartureDateTo);
}

3. Extra Checks to Guarantee Callbacks Fire #

• Add Internet Permission (if this is an Android project): Make sure your AndroidManifest.xml includes:

  <uses-permission android:name="android.permission.INTERNET" />
  

• Verify Your Response Model: Double-check that GetCheapestResponseType matches the JSON structure returned by the Ryanair API. Mismatched fields or missing Gson annotations could cause silent parsing failures.
• Add Logging for Debugging: Use OkHttp's logging interceptor to see exactly what's being sent/received. Add this to your OkHttpClient builder:

  HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
  logging.setLevel(HttpLoggingInterceptor.Level.BODY);
  httpClient.addInterceptor(logging);
  

  This will print full request/response details in your logcat, making it easy to spot URL issues, missing parameters, or API errors.

After fixing these two main issues, your Retrofit call should start triggering the callbacks as expected.

内容的提问来源于stack exchange，提问作者janusz j