Android: Jsoup login - https

Question

How is it possible to login programmatically on to a website ?

Example: The User type in his login data in EditText and click on the login Button. Then opens a WebView, where he is logged in.

I tried to work with these code examples but:

How to connect via HTTPS using Jsoup? - i got Errors

How to log in to an HTTPS website with Jsoup? - i didnt got Errors but i cant login

Jsoup HTTPS connecting - it dont work i got Errors

After i used this, i tried this

class JsoupAsyncIserv extends AsyncTask<Void, Void, Void> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected Void doInBackground(Void... params) {
        //HTML Parsen
        try {


            Connection.Response login = Jsoup.connect("https://lmg-nhs.de/idesk")
                    .data("login_act", "MyUsername")
                    .data("login_pwd", "MyPW")
                    .method(Connection.Method.POST)
                    .execute();

            Document document = Jsoup.connect("https://lmg-nhs.de/idesk")
                    .cookies(login.cookies())
                    .get();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {


    }
}

It works, but i cant login.

private class IServAsyncTask extends AsyncTask<Void, Void, Void>{

        private String resp;
        protected String doInBackground(String... params) {
            Connection.Response res = null;
            try {
                res = Jsoup.connect("https://lmg-nhs.de")
                        .data("login_act", "myUsername")
                        .data("login_pwd", "myPW")
                        .data("submit", "Anmelden")
                        .method(Connection.Method.POST)
                        .execute();

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

            try {
                Document doc = res.parse();
            } catch (IOException e) {
                e.printStackTrace();
            }
            String sessionId = res.cookie("PHPSESSID");

            try {
                Document doc2 = Jsoup.connect("https://lmg-nhs.de")
                        .cookie("PHPSESSID", sessionId)
                        .get();
            } catch (IOException e) {
                e.printStackTrace();

            }

            return resp;
        }

        @Override
        protected Void doInBackground(Void... voids) {
            return null;
        }
    }

If you can, try to explain it at an or my example, because beginners (like me) can easier learn it this way.

Using Chrome open dev tools and open the Network tab, mark to Preserve log, clear cookies/cache, then log into the page an inspect the request and responses. You should try to set all needed header fields (and setting a user-agent is usually a good idea). A general example is often too general (but they exist: http://stackoverflow.com/documentation/jsoup/4631/logging-into-websites-with-jsoup) and without having an account we can't provide a specific solution. — Frederic Klein, Sep 26 '16 at 09:34
A better way for your login might be: open a webview (without displaying it), fill and submit the login form using javascript, then display the webview. — Frederic Klein, Sep 26 '16 at 09:48
Are sure `String doInBackground(String... params)` gets called and not `Void doInBackground(Void... voids)`? — Stephan, Sep 26 '16 at 10:07
@F.Klein I know that help is very difficulty but thank you for trying it! I tried it with the first example form [http://stackoverflow.com/documentation/jsoup/4631/logging-into-websites-with-jsoup] but i cant login. I need the login to show a logged in WebView and to download something without WebView. If you have any other ideas or helps then let it hear me. All can help me ! — Excel1, Sep 26 '16 at 16:02
@Stephan i found only a Jsoup Example with Asynctask in this way `Void doInBackground(Void... voids)` I tried to work with this example but i have no ideas to fix it. If you have a better way to do this, let it hear me. — Excel1, Sep 26 '16 at 16:05
@F.Klein do you maybe know a other way to loggin in ? Maybe with the WebView ? — Excel1, Sep 28 '16 at 13:07

score 2 · Answer 1 · edited Sep 25 '17 at 18:37

Try this:

Document doc2 = Jsoup.connect("https://lmg-nhs.de")
                    .cookie(res.cookies())
                    .get();

instead of

Document doc2 = Jsoup.connect("https://lmg-nhs.de")
                    .cookie("PHPSESSID", sessionId)
                    .get();

// # Constants used in this example
final String USER_AGENT = "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36"; 
final String LOGIN_FORM_URL = "https://github.com/login";
final String USERNAME = "yourUsername";  
final String PASSWORD = "yourPassword";  

// # Go to login page
Connection.Response loginFormResponse = Jsoup.connect(LOGIN_FORM_URL)
                                             .method(Connection.Method.GET)
                                             .userAgent(USER_AGENT)
                                             .execute();  

// # Fill the login form
// ## Find the form first...
FormElement loginForm = (FormElement)loginFormResponse.parse()
                                         .select("div#login > form").first();
checkElement("Login Form", loginForm);

// ## ... then "type" the username ...
Element loginField = loginForm.select("#login_field").first();
checkElement("Login Field", loginField);
loginField.val(USERNAME);

// ## ... and "type" the password
Element passwordField = loginForm.select("#password").first();
checkElement("Password Field", passwordField);
passwordField.val(PASSWORD);        


// # Now send the form for login
Connection.Response loginActionResponse = loginForm.submit()
         .cookies(loginFormResponse.cookies())
         .userAgent(USER_AGENT)  
         .execute();

System.out.println(loginActionResponse.parse().html());

public static void checkElement(String name, Element elem) {
    if (elem == null) {
        throw new RuntimeException("Unable to find " + name);
    }
}

All the form data is handled by the FormElement class for us (even the form method detection). A ready made Connection is built when invoking the FormElement#submit method. All we have to do is to complete this connection with addional headers (cookies, user-agent etc) and execute it.

Thank you for your answer. I tried it but `res` from `.cookie(res.cookies())` got not defined. I defined it `Connection.Response res = null;` but Android Studio try it do surround it with `res != null` and i got an error. — Excel1, Sep 26 '16 at 15:50
@Excel1 Rewrite your code to use only one `try` block and not three. — Stephan, Sep 26 '16 at 16:31
i tried but it didnt worked. `.cookie(res.cookies())` _cannot be applied_ If you have a code example maybe i can try it and learn it. Thank you for help — Excel1, Sep 27 '16 at 08:27
@Excel1 Please see the link to the documentation (http://stackoverflow.com/documentation/jsoup/4631/logging-into-websites-with-jsoup/23695/logging-with-formelement#t=201609261108016427445) in my post. — Stephan, Sep 27 '16 at 08:47
i need only a way to log successfully in on this page. Jsoup was the "best" method i found but i dont know it with and without jsoup. — Excel1, Sep 27 '16 at 14:30
And do i need it to put this in Async Task ? And if i need to do this then please tell me how — Excel1, Sep 27 '16 at 14:36
http://pastebin.com/iDrCRkhw there i did it on 2 Ways... problem: `String authToken = loginDoc.select("#login > form > div:nth-child(1) > input[type=\"hidden\"]:nth-child(2)") .first() .attr("value");` because: Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String org.jsoup.nodes.Element.attr(java.lang.String)' on a null object reference — Excel1, Sep 27 '16 at 15:24

Android: Jsoup login - https

1 Answers1

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