Jsoup - read from an html url where code is hidden - java

I'm trying to using the jsoup library to get 'li' from a website. The problem is this:
If I open the source of website with CTRL+U(which is the same read by jsoup), the 'ul' tag is hidden.
if I open the code with the fuction "inspect code" of google chrome,'li' are shown.
Posting the code is not necessary; I only want to know how can access to this 'li' with jsoup or other java free libraries, Whereas in the source code(and through jsoup) these informations are hidden.
The site is https://farmaci.agenziafarmaco.gov.it/bancadatifarmaci/cerca-farmaco and try to search something(i.e. Tachi)

The problem with Jsoup is that it won't handle scripts. It is just getting html as it is before the AJAX code is executed.
You can use something like HtmlUnit, which is basically a GUI-less browser. So, it can handle scripts.
You can try something like this after getting the HtmlUnit library:
String url = "https://farmaci.agenziafarmaco.gov.it/bancadatifarmaci/cerca-farmaco?search=Tachi";
try(final WebClient webClient = new WebClient()) {
final HtmlPage page = webClient.getPage(url);
final HtmlUnorderedList list = page.getHtmlElementById("ul_farm_results");
System.out.println(list.asText());
}
I couldn't check the code as the website's certificate is improperly configured and I didn't want to import it's certificate. You may want to take a look at this to resolve the certificate errors.

JSoup does not execute all the scripts, it just gets the HTML returned by the server. What you are looking for is call rendered HTML, that is the HTML produced by the browser after executing all the scripts.
The best solution in Java is to use Selenium with your preferred browser. Selenium was developed for UI testing, it is however very popular as a scraping tool.
A good getting started page is to be found here.
Some code example with Firefox:
WebDriver driver = new FirefoxDriver();
driver.get("https://farmaci.agenziafarmaco.gov.it/bancadatifarmaci/cerca-farmaco");
// Find the element
String id = "ul_farm_results";
WebElement element = driver.findElement(By.id(id));

Related

Java Jsoup Submitting a form

I am trying to figure out how to submit a form using Jsoup.
On Xfinity's website, I am trying to input an address and get back the resulting page after clicking on "Show me deals" from the url below:
https://www.xfinity.com/learn/offers
Here is my current code:
public String getISP() throws IOException {
Connection.Response addressFormResponse = Jsoup.connect("https://www.xfinity.com/learn/offers")
.data("Address.SingleStreetAddress", address)
.method(Connection.Method.POST)
.execute();
Document doc = addressFormResponse.parse();
System.out.println(doc.title());
System.out.println(doc.location());
if (doc.location().contains("Active Address")) {
return "Comcast XFinity";
}
return "Cannot find an ISP";
}
The current code only returns the same webpage, how would I get back the resulting page?
Jsoup is a HTML parser library, it provides functionality for extracting and manipulating data on HTML page. If you need traverse websites, submit forms, click elements, it's better to use another tools, like selenium, HTTP client (which are often used for automated test of web applications) or web crawler libraries like crawler4j.
I would tend to disagree with Daniil's answer in that neither HTTP Client or crawler4j support javascript which is required for this page. Selenium is probably the best solution.
What follows is an example of how to use jsoup to fetch a page, fill out a form, and submit it. The result is json and so you would then pass that string to gson or similar. I did not that the page was very flaky just in a regular browser, and sometimes would catch the address input and sometimes would barf on the same input.
Document doc = Jsoup.connect("https://www.xfinity.com/learn/offers").get();
FormElement form = (FormElement) doc.selectFirst("[data-form-dealfinder-localization]");
Element input = form.selectFirst("#Address_StreetAddress");
input.val("2000 YALE AVE E, SEATTLE, WA 98102");
String json = form.submit().ignoreContentType(true).execute().body();
System.out.println(json);

Going to next page on an aspx form with JSoup

I'm trying to go to the next page on an aspx form using JSoup.
I can find the next button itself. I just don't know what to do with it.
The idea is that, for that particular form, if the next button exists, we would simulate a click and go to the next page. But any other solution other than simulating a click would be fine, as long as we get to the next page.
I also need to update the results once we go to the next page.
// Connecting, entering the data and making the first request
...
// Submitting the form
Document searchResults = form.submit().cookies(resp.cookies()).post();
// reading the data. Everything up to this point works as expected
...
// finding the next button (this part also works as expected)
Element nextBtn = searchResults.getElementById("ctl00_MainContent_btnNext");
if (nextBtn != null) {
// click? I don't know what to do here.
searchResults = ??? // updating the search results to include the results from the second page
}
The page itself is www.somePage.com/someForm.aspx, so I can't use the solution stated here:
Android jsoup, how to select item and go to next page
I was unable to find any other suggestions.
Any ideas? What am I missing? Is simulating a click even possible with JSoup? The documentation says nothing about it. But I'm sure people are able to navigate these type of forms.
Also, I'm working with Android, so I can't use HtmlUnit, as stated here:
importing HtmlUnit to Android project
Thank you.
This is not Jsoup work! Jsoup is a parser with a nice DOM API that allows you to deal with wild HTML as if it were well-formed and not crippled with errors and nonsenses.
In your specific case you may be able to scrape the target site directly from your app by finding links and retrieving HTML pages recursively. Something like
private void scrape(String url) {
Document doc = Jsoup.connect(url).get();
// Analyze current document content here...
// Then continue
for (Element link : doc.select(".ctl00_MainContent_btnNext")) {
scrape(link.attr("href"));
}
}
But in the general case what you want to do requires far more functionality that Jsoup provides: a user agent capable of interpreting HTML, CSS and Javascript with a scriptable API that you can call from your app to simulate a click. For example Selenium:
WebDriver driver = new FirefoxDriver();
driver.findElement(By.name("next_page")).click();
Selenium can't be bundled in an Android app, so I suggest you put your Selenium code on a server and make it accessible with some REST API.
Pagination on ASPX can be a pain. The best thing you can do is to use your browser to see the data parameters it sends to the server, then try to emulate this in code.
I've written a detailed tutorial on how to handle it here but it uses the univocity HTML parser (which is commercial closed source) instead of JSoup.
In short, you should try to get a <form> element with id="aspnetForm", and read the form elements to generate a POST request for the next page. The form data usually comes out with stuff such as this:
__EVENTTARGET =
__EVENTARGUMENT =
__VIEWSTATE = /wEPDwUKMTU0OTkzNjExNg8WBB4JU29ydE9yZ ... a very long string
__VIEWSTATEGENERATOR = 32423F7A
... and other gibberish
Then you need to look at each one of these and compare with what your browser sends. Sometimes you need to get values from other elements of the page to generate a similar POST request. You may have to REMOVE some of the parameters you get - again, make your code behave exactly the same as your browser
After some (frustrating) trial and error you will get it working. The server should return a pipe-delimited result, which you can break down and parse. Something like:
25081|updatePanel|ctl00_ContentPlaceHolder1_pnlgrdSearchResult|
<div>
<div style="font-weight: bold;">
... more stuff
|__EVENTARGUMENT||343908|hiddenField|__VIEWSTATE|/wEPDwU... another very long string ...1Pni|8|hiddenField|__VIEWSTATEGENERATOR|32423F7A| other gibberish
From THAT sort of response you need to generate new POST requests for the subsequent pages, for example:
String viewState = substringBetween(ajaxResponse, "__VIEWSTATE|", "|");
Then:
request.setDataParameter("__VIEWSTATE", viewState);
There are will be more data parameters to get from each response. But a lot depends on the site you are targeting.
Hope this helps a little.

HtmlUnit does not find the element

I'm trying to get the textbox with u_0_1e as id, from the page wall but HtmlUnit does not find anything. The last line prints null.
Here's the code:
java.util.logging.Logger.getLogger("com.gargoylesoftware").setLevel(java.util.logging.Level.OFF);
WebClient client = new WebClient(BrowserVersion.CHROME);
JavaScriptEngine engine = new JavaScriptEngine(client);
client.setJavaScriptEngine(engine);
HtmlPage home = client.getPage("https://www.facebook.com/login.php");
HtmlSubmitInput login = (HtmlSubmitInput) home.getElementById("u_0_1");
HtmlTextInput name = (HtmlTextInput) home.getElementById("email");
HtmlPasswordInput pass = (HtmlPasswordInput) home.getElementById("pass");
name.setValueAttribute("myname");
pass.setValueAttribute("mypass");
HtmlPage page = login.click();
HtmlPage wall = client.getPage("https://www.facebook.com/");
System.out.println(wall.getElementById("u_0_1e"));
I have some comments about your issue.
First of all, you have disabled HtmlUnit's logging. So if you have any JavaScript issue then you are not going to see it. If you are actually getting a JavaScript error then the JavaScript code won't be fully executed. If the element you're trying to fetch was dynamically fetched from the server (probably using AJAX) then the JavaScript errors, if any, might result in that element not being fetched.
If you are webscraping, which is clearly the case, then you don't have any control over the JS so you can only accept it as not working or disable JS and manually processing the AJAX requests.
Of course, you will see the page perfectly working on a real browser but take into consideration that the JavaScript engine HtmlUnit uses is different from the real browsers.
Secondly, the two lines containing the word engine are absolutely unneeded.
Thirdly, as I mentioned in a previous question of yours, this will be more suitable to be handled by means of the Facebook API.
Finally, you might find this other answer useful:
JavaScript not being properly executed in HtmlUnit

Prevent HtmlUnit 2.13 from executing JavaScript

Here is my code to get the page:
WebClient webClient = new WebClient();
HtmlPage page = webClient.getPage(url);
The problem is the webClient always executes javascript automatically and throws me a list of error. I just want to get the raw source. How can I prevent it from executing script? I've found there is a way in version 2.9:
webClient.setJavaScriptEnabled(false);
But setJavaScriptEnabled() function was deprecated. Anyone knows how to solve this problem? Please help me. Thank you so much.
Although setJavaScriptEnabled(boolean) was deprecated it was added to the WebClientOptions member of the WebClient. Here is the doc.
In order to disable JavaScript you should do this:
webClient.getOptions().setJavaScriptEnabled(false);
Additionally, if you you want to get the raw HTML code from the webpage you should take a look at this question:
How to get the pure raw HTML of a page in HTMLUnit while ignoring JavaScript and CSS?
Take into account that even the asXml() method change the formatting as well as the content of the web page you fetch (even if JavaScript is disabled).

The Web Browser show the correct values but when I use Jsoup the HTML doesn't have the values

I'm trying to get some values from a site but these values only appears when I use a Browser, like Mozilla. When I use the Jsoup I can get the HTML from the site but without values, only with the tags.
This is the site I'm trying to parse:
http://www.submarinoviagens.com.br/Passagens/selecionarvoo?Origem=nat&Destino=mia&Data=05/11/2012&Hora=&Origem=mia&Destino=nat&Data=09/11/2012&Hora=&NumADT=1&NumCHD=0&NumINF=0&SomenteDireto=0&Cia=&SelCabin=&utm_source=&utm_medium=&utm_campaign=&CPId=
I'm trying to get the values that appears inside these span tags:
If I access the previous URL from a web browser I can see the following values: '', 'R$ 2634,22' and 'R$ 2634,22', but when I use the following code the values disapears.
URL url = new URL("http://www.submarinoviagens.com.br/Passagens/selecionarvoo?Origem=nat&Destino=mia&Data=05/11/2012&Hora=&Origem=mia&Destino=nat"+
"&Data=09/11/2012&Hora=&NumADT=1&NumCHD=0&NumINF=0&SomenteDireto=0&Cia=&SelCabin=&utm_source=&utm_medium=&utm_campaign=&CPId=");
Document doc = Jsoup.parse(url, 100000);
String title = doc.title();
System.out.println(doc.toString());
If I try to see the source code via Mozilla Firefox the values disapears too.
But If I use the firebug plugin I can see them.
Thank's for the help!
The website uses JavaScript to populate all of the values you are trying to parse. You will have to use a library that can compute the javascript within the page. Not sure if there is one though.
anyone else?
Htmlunit is a headless browser that renders Javascript and should be able to present this page correctly.

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