由Volley的onResponse设置的访问变量

我有两个全局变量 currentTemp 和 currentHum 当截击结束时设定的 onResponse 方法被调用。我的代码如下所示:

// Request a string response from the provided URL.
    private JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, WEATHER_URL, null, new Response.Listener<JSONObject>() {
        public void onResponse(JSONObject response) {
            try {
                JSONObject main = new JSONObject(response.getString("main"));
                currentTemp = main.getString("temp");
                currentHum = main.getString("humidity");
                Log.i("RES", "Temp: " + main.getString("temp") + " Hum: " + main.getString("humidity"));
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }}, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            Toast.makeText(appContext, "An error occurred while retrieving weather info", Toast.LENGTH_LONG).show();
            Log.e("ERR", "ERROR RET WEATHER DATA");
        }
    });


    // Call the OpenWeatherMap API and get data such as temperature and humidity
    private String getWeatherInfo(String key) {
        // Add the request to the RequestQueue to invoke the API
        queue.add(jsonObjectRequest);
        // Access variables set by Volley's onResponse here.
        switch (key) {
            case "temp":
                return String.valueOf(Float.parseFloat(currentTemp) - 273.15);
            case "hum":
                return currentHum;
            default:
                return " ";
        }
    }

我希望能够访问 回应 方法 getWeatherInfo 调用它的方法。然后将这些值传递给switch语句进行处理。如何在不获取空值的情况下执行 电流温度 和 哼 ?