Java: Accessing a String outside of a function

I am a hobby programmer and am trying to access returnJson outside of the onSuccess function. Inside of the function, I can see that it returns as expected. Could somebody explain why I cannot view it outside and what I can do to make it accessible on the outside?

String returnJson;, url, entity, "application/json", new JsonHttpResponseHandler() {
    public void onSuccess(int statusCode, Header[] headers, JSONObject response) {
        returnJson = response.toString();

Log.d("get json",returnJson);


You can access it fine, but it is not initialized until the onSuccess() is called, which is likely after the Log.d() is called, due to being executed asyncronously.

Because of this, at the moment you try to log returnJson, it is not yet initialized and the logging won’t work as you expect.