How can I login to a website (meta refresh) with Jsoup?

Question

I'm trying to login using this.

res = Jsoup.connect("http://www.registru.liceu.asm.md/elev/login.php?user=Vozian_Valentin")
                   .data("pass", "DyXnyU")
                   .data("class","Clasa11B")
                   .data("submit","log in")
                   .method(Method.POST)
                   .execute();

When I call res.parse().outerHtml() it shows something diferent from successfully logged page or incorrect logged page and if I change the password to incorrect it shows the incorrect logged page.

Answer 1

Once you're logged in, the server returns an HTML page with a Refresh meta tag. Since Jsoup is an HTML parser, it can't handle this kind of redirect automatically. It has to be told to do so.

Here is how to do it:

private static final String UA_STRING = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:40.0) Gecko/20100101 Firefox/40.1";
private static final String REFRESH_URL = "refresh-url";
private String loginFormUrl = "http://www.registru.liceu.asm.md/elev/login.php?user=Vozian_Valentin";

// Go to login form page
Response res = Jsoup.connect(loginFormUrl) //
                    .userAgent(UA_STRING) //
                    .data("pass", "DyXnyU") //
                    .data("class","Clasa11B") //
                    .data("submit","log in") //
                    .method(Method.POST) //
                    .execute();

// Extract the Refresh meta tag from server response
Element meta = res.parse().select("meta[http-equiv=Refresh]").first();
if (meta==null) {
    throw new RuntimeException("Unable to locate Refresh meta tag...");
}

// Determine the refresh url from the meta tag
String content = meta.attr("content");
meta.attr(REFRESH_URL, content.replaceAll("(?i)^(\\d+;.+URL=)(.+)$", "$2"));

// Go to refresh url
Response res2 = Jsoup //
  .connect(meta.absUrl(REFRESH_URL)) //
  .userAgent(UA_STRING) // 
  .referrer(loginFormUrl) //
  .method(Method.GET) //
  .cookies(res.cookies()) //
  .execute();

// Get the successfully logged page
System.out.println(res2.parse().outerHtml());