Interface Callback

retrofit/src/main/java/retrofit2/Callback.java:32–46

Communicates responses from a server or offline requests. One and only one method will be invoked in response to a given request. Callback methods are executed using the Retrofit callback executor. When none is specified, the following defaults are used: Android: Callbacks ar

 * @param <T> Successful response body type.
 */
public interface Callback<T> {
  /**
   * Invoked for a received HTTP response.
   *
   * <p>Note: An HTTP response may still indicate an application-level failure such as a 404 or 500.
   * Call {@link Response#isSuccessful()} to determine if the response indicates success.
   */
  void onResponse(Call<T> call, Response<T> response);

  /**
   * Invoked when a network exception occurred talking to the server or when an unexpected exception
   * occurred creating the request or processing the response.
   */
  void onFailure(Call<T> call, Throwable t);
}