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Android Build a Weather App (2015) Concurrency and Error Handling Handling Errors

Posted by Nicolas Hampton
Nicolas Hampton
44,638 Points

Why don't we define the Callback object in a separate variable?

I noticed that we're defining the Callback() {} inside the call.enqueue() method. Doesn't that limit it's scope, and thus it's usefulness? Why aren't we defining it outside of the method as a member variable so we can use it again if needed, or simply for readability? Like:

Callback callback = new Callback() {
   @Override
   public void onFailure(Request request, IOException e) {}

   @Override
   public void onResponse(Response response) throws IOException {
      try {
          if(reposnse.isSuccessful()) {
             Log.v(TAG, response.body().string());
          }
       } catch (IOException e) {
           Log.e(TAG, "Exception caught: ", e);
         }
     }
}

call.enqueue(callback());

Am I missing something? Does this inherently not work if initialized outside of the enqueue method? This seems a lot clearer and pliable to me.

Ryan Deas
Ryan Deas
1,027 Points
Ryan Deas
Ryan Deas
1,027 Points

Generally, people don't write callbacks into variables as they are usually pretty specific for the case that they're being written in. Also there would be an issue with your code as you wouldn't call the callback variable with () as you only put () when you are calling a method, in this case you're calling a variable.