Getting id wrong

Question

In the small project I am doing, the user enters his login and password. The system makes a POST for a URL and checks the answer. If you log in, it returns some things like the user ID, email and everything else.

I need to get the user ID so I can subscribe to an MQTT topic, but I’m having trouble getting this ID! I’ve been able to map and separate from JSON, but when I try to use it I’m always getting zero. I will post the classes below (at least the relevant parts).

Class responsible for doing the post (when called):

public class SenderPost {
    private HttpResponse response;

    public int getIdReceived() {
        return idReceived;
    }

    private void setIdReceived(int idReceived) {
        this.idReceived = idReceived;
    }

    private int idReceived;

    int postLogin(String login, String password) throws UnsupportedEncodingException {

       //(código omitido) configurações do POST

        try {
            response = client.execute(post);
            HttpEntity entidade = response.getEntity();
            String responseString = EntityUtils.toString(entidade, "UTF-8");
            DOMInfoLogin dil = new ObjectMapper().readValue(responseString, DOMInfoLogin.class); // aqui eu mapeio o JSON pra poder usar os atributos
            setIdReceived(dil.getId()); //aqui eu coloco o atributo idReceived como o id que recebo do JSON

      }
       //(código omitido) tratativas de erro 

        return response.getStatusLine().getStatusCode();
    }
}

This is the class that runs Senderlogin and checks its response (to see if it’s logged in, and if not logged in, why):

public class AutenticaLogin {

    public SenderPost post = new SenderPost();

    boolean autenticaLogin(TextField txtID, PasswordField pwdField, Button btnLogin) throws IOException {
        btnLogin.setDisable(false);
        switch (post.postLogin(txtID.getText(), pwdField.getText())) {
            case 200:
                return true;
//(código omitido) Tratativas para outros status code
        }
    }
}

Finally, the method where the error is effective (this method is in another class, but I’ll omit it and leave only the method): I try to concatenate my String with the information and then I get it. (Before using the set method, I received NPE)

 private AutenticaLogin auth = new AutenticaLogin();

    public void connect() throws MqttException, IOException {
    //(código omitido) Configurações do MQTT
    String topic = "topico/"+auth.post.getIdReceived()+"/start";
//(código omitido) Conexões do MQTT
}

And here in the debug is the problem, but I don’t know how to solve (I was supposed to get 195)

Answer 1

The solution was to create static attribute and set method, and when I get the ID, attribute in the class. I don’t know if it’s ideal, but it works well for what I need.

private static String getIdReceived() {
    return idReceived;
}
switch (post.postLogin(txtID.getText(), pwdField.getText())) {
            case 200:
                MqttBase.setIdReceived(post.getIDClient());
                MqttBase.setEmpresaReceived(post.getIDEmpresa());
                return true;
//código omitido

Answer 2

Missed you calling the method autenticationLogin to feed its variable idReceived class SenderPost

 private AutenticaLogin auth = new AutenticaLogin();

    public void connect() throws MqttException, IOException {
    //(código omitido) Configurações do MQTT

    auth.autenticaLogin(txtID, pwdField, btnLogin);

    String topic = "topico/"+auth.post.getIdReceived()+"/start";
//(código omitido) Conexões do MQTT
}

If you don’t call the autenticationLogin you will never call the postLogin, which in turn will feed the variable idReceived.