如何從Retrofit onResponse方法返回數據？

Question

我是新的改造，我想讓我的getData方法返回一個功能對象。什麼是最簡單的方法來做到這一點？

DataService.java

public class DataService { 

    private static final String TAG = MainActivity.class.getSimpleName(); 
    private final ApiClient apiClient; 

    public DataService() { 
     apiClient = new ApiClientFactory().createApiClient(); 
    } 

    public List<Feature> getData(){ 

     apiClient.getData().enqueue(new Callback<DataResponse>() { 

      @Override 
      public void onResponse(Call<DataResponse> call, Response<DataResponse> response) { 
       List<Feature> features = response.body().getFeatures(); 
       Log.d(TAG, "Data successfully downloaded"); 
      } 

      @Override 
      public void onFailure(Call<DataResponse> call, Throwable t) { 
       Log.e(TAG, t.toString()); 
      } 
     }); 
     //I need to return features in getData method 
    } 
} 

Answer 1

你不能return，你必須 「回電話」。

將內部回調類提取到參數中。

public void getData(Callback<DataResponse> callback){ 
    apiClient.getData().enqueue(callback); 
} 

在你的其他代碼

// DataService service = ...; 

// Define Callback 
Callback<DataResponse> responseCallback = new Callback<DataResponse>() { 

    @Override 
    public void onResponse(Call<DataResponse> call, Response<DataResponse> response) { 
     List<Feature> features = response.body().getFeatures(); 
     Log.d(TAG, "Data successfully downloaded"); 

     // Data is returned here 
     for (Feature f: features) { 
      Log.d("feature", String.valueOf(f)); // for example 
     } 
    } 

    @Override 
    public void onFailure(Call<DataResponse> call, Throwable t) { 
     Log.e(TAG, t.toString()); 
    } 
}; 

// Call it 
service.getData(responseCallback); 

你也可以做service.getData(new Callback<DataResponse>() { ... });