REQUISIÇÃO HTTP retorna Connection refused

POST.

        try {
            URL url = new URL("http://127.0.0.1:8000/api/alunos");
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestProperty("Content-type","Application/json");
            connection.setRequestProperty("Accept","Application/json");

            connection.setDoOutput(true);

            PrintStream output  = new PrintStream(connection.getOutputStream());
            output.println(json);

            connection.connect();

            Scanner scanner = new Scanner(connection.getInputStream());
            String resposta = scanner.next();

            return resposta;

        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return null;

Chamada:

new EnviaAlunosTask(this).execute();

Manifest.

    <uses-permission android:name="android.permission.CALL_PHONE" />
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />