Error making android HTTP request

Question

I’m implementing a native android app that requests with a WS. When trying to make the connection in the method connect() of HttpURLConnection I’m getting an error that doesn’t fall into the catch to be validated.

Doing some research I found that the error occurs by the port I reported in my connection URL because my server is local. I set the door number 80886 for example. With this I received the error java.lang.IllegalArgumentException: port=80886. Researching a little more understood that the maximum number of accepted ports is 65535 and in fact if I put the door 65536 I get the same error mentioned earlier, a smaller port not problems.

So far it is even understandable because I saw that it has connection with the TCP protocols and this magic number 65535 is actually the maximum number since it is the calculation of 2 16. Since port identifiers are 16-bit integers, this is the maximum accepted value.

I tested using 2 different devices. One with version 4.4.4 of android and another with version 8.0.0. On device with version 4.4.4 error occurred, already on android 8.0.0 had no problems.

Could you explain to me why this happened? Why error only occurs in old version?

Method Code:

public static boolean testarConexaoServidor(String url) {

    boolean retorno = false;
    int milissegundos = 20000;

    try {
        URL apiEnd = new URL(url);
        int codigoResposta;
        HttpURLConnection conexao;

        conexao = (HttpURLConnection) apiEnd.openConnection();
        conexao.setRequestMethod("GET");
        conexao.setReadTimeout(milissegundos);
        conexao.setConnectTimeout(milissegundos);
        conexao.connect();

        codigoResposta = conexao.getResponseCode();
        if (codigoResposta < HttpURLConnection.HTTP_BAD_REQUEST) {
            retorno = true;         
        }

        conexao.disconnect();


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

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

    return retorno;
}