How to open an Activity when you don’t have internet?

Question

I’m with a project that uses internet, and when there is no internet the same does not leave the menu because I put a lock access to other activit when there is no internet, but in did not open I wanted to play to another specific Action, I can even open a random blank page but the page I request to open does not come, I need help

MENU CODE

public class TRABALHAR extends AppCompatActivity {

private WebView xp4;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_trabalhar);

    if(!isOnline()){
        startActivity(new Intent(TRABALHAR.this,NOTICIAS2.class));
        finish();
    }// verifica conexao com a net


    xp4 = findViewById(R.id.xp4);
    xp4.getSettings().setJavaScriptEnabled(true);
    xp4.setWebViewClient(new WebViewClient());
    xp4.loadUrl("https://clubcooeec1.blogspot.com/p/fazer-parte-da-equipe.html");

}
public boolean isOnline() {
    ConnectivityManager cm = (ConnectivityManager)
            getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo netInfo = cm.getActiveNetworkInfo();
    return netInfo != null && netInfo.isConnected(); // verifica se tem internet
}

if I take the line

startActivity(new Intent(WORK.this,NOTICIAS2.class));

the application just blocks access to page, but this is not my goal

how I should proceed in this case ?

Answer 1

I made some changes and tested on an API 24, it worked well.

First create an Asynctask extended class, as follows:

public class CarregaPagina extends AsyncTask<String, Void, Boolean> {
    TRABALHAR trabalhar;
    String sUrl;
    int timeout;

    //construtor
    public CarregaPagina(TRABALHAR trabalhar, String sUrl, int timeout) {
        this.trabalhar = trabalhar;
        this.sUrl = sUrl;
        this.timeout = timeout;

    }

    @Override
    protected Boolean doInBackground(String... strings) {
        //se tem algum conexão com a internet
        if (isOnline()) {
            //checa a conexão com a url
            try {

                URL url = new URL(sUrl);
                //abre a conexão
                URLConnection urlConnection = url.openConnection();
                //tempo de resposta
                urlConnection.setConnectTimeout(timeout);
                //conecta
                urlConnection.connect();
                return true;
            } catch (MalformedURLException e) {
                e.printStackTrace();
                return false;
            } catch (IOException e) {
                e.printStackTrace();
                return false;
            }
        } else {
            return false;
        }
    }

    @Override
    protected void onPostExecute(Boolean b) {
        if (b) {
            WebView xp4 = trabalhar.xp4;

            //carrega webview da classe TRABALHAR
            xp4.getSettings().setJavaScriptEnabled(true);
            xp4.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
            xp4.getSettings().setLoadWithOverviewMode(true);
            xp4.getSettings().setUseWideViewPort(true);
            xp4.setWebViewClient(new WebViewClient());
            xp4.loadUrl(sUrl);
        } else {
            Toast.makeText(trabalhar, "Erro na conexão", Toast.LENGTH_SHORT).show();
            //Erro na conexão
            chamaActivity();
        }

    }

    private void chamaActivity() {
        Intent i = new Intent(trabalhar, NOTICIAS2.class);
        i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        trabalhar.startActivity(new Intent(trabalhar, NOTICIAS2.class));
        trabalhar.finish();
    }

    public boolean isOnline() {
        ConnectivityManager cm = (ConnectivityManager) trabalhar.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo netInfo = cm.getActiveNetworkInfo();
        return netInfo != null && netInfo.isConnected(); // verifica se tem internet
    }
}

This class will be responsible for checking if the user is connected to the internet and if it is possible to load its url, if it is not able to load the url in the webview, its Acitivty NOTICIAS2 will be called.

Already in your class WORK, just let:

public class TRABALHAR extends AppCompatActivity {
    //deixe público pra poder utilizar na classe CarregaPagina;
    public WebView xp4;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_trabalhar);
        xp4 = findViewById(R.id.xp4);

        //os parametros na ordem são: contexto, url, e timeout (tempo pra checar a url) em milisegundos.
        CarregaPagina carregaPagina = new CarregaPagina(this, "https://clubcooeec1.blogspot.com/p/fazer-parte-da-equipe.html", 2000);
        //executa a AsyncTask
        carregaPagina.execute();

    }
}