使用servlet从外部页面获取数据

Question

I'm doing my first college HTML project wich I need to get data from an external Webpage using servlets.

First, on the website, I need to enter a key code and fill one captcha to get to the page I need. I'm leaving the captcha to the user, planning to load the page on a div or iframe, and when the user hit Next, I'll hide it and process the data using the servlets.

The page is: http://www.nfe.fazenda.gov.br/portal/consulta.aspx?tipoConsulta=completa&tipoConteudo=XbSeqxE8pl8=

I'm using:

<iframe id="iframeSEFAZ" src="http://www.nfe.fazenda.gov.br/portal/consulta.aspx?tipoConsulta=completa&tipoConteudo=XbSeqxE8pl8=#ctl00_ContentPlaceHolder1_pnlInformacoesConsulta"></iframe>

After I fill the data, I'm able to see the data I want. But I wonder how do I transfer (buffer?) my current page (the iframe after I fill the captcha) to the servlet.

I already have the method to parse the page:

public void parse_pagina (String pagina) {
DataBaseColetor db = new DataBaseColetor ();
db.openConnectionDB();

try {
  Document doc = Jsoup.parse (pagina); 

  String texto_html = doc.html ();
  System.out.println ("\n\n Página coletada: \n\n " + texto_html);


  Elements div = doc.select ("[id=\"divImpressao\"]"); //Seleciona o elemento com id = "divImpressao".

  this.armazenarElemento (db, "div", "conteudo", "", "", div); 

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

}

I'm new to web development, so all the help is much appreciated. And sorry for my bad english.

Answer 1

Store the value which you want to share across pages, in a session attribute for the first time.

Access it in any page with the session.

Eg. sessionObj.setAttribute("sharedVariable","abc"); // at the page where your element comes first

Then wherever you want this data. Use the session attribute name.

Eg. String s = (String) sessionObj.getAttribute("sharedVariable");

Answer 2

After searching around I learned that cross site contents like my iframe can not be read by javascript. So I'm doing this server side.