CODEWITHSUNDEEP
javascriptjavahtmlkotlinjsoup
ravi
ravi

Reputation: 6328

Parse JavaScript with jsoup

In an HTML page, I want to pick the value of a javascript variable.
Below is the snippet of HTML page:

<input id="hidval" value="" type="hidden"> 
<form method="post" style="padding: 0px;margin: 0px;" name="profile" autocomplete="off">
<input name="pqRjnA" id="pqRjnA" value="" type="hidden">
<script type="text/javascript">
    key="pqRjnA";
</script>

My aim is to read the value of variable key from this page using jsoup.
Is it possible with jsoup? If yes then how?

Upvotes: 16

Views: 43086

Answers (2)

Mahozad
Mahozad

Reputation: 24522

The Kotlin question is marked as duplicate and is directed to this question.
So, here is how I did that with Kotlin:

val (key, value) = document
    .select("script")
    .map(Element::data)
    .first { "key" in it } // OR single { "key" in it }
    .split("=")
    .map(String::trim)
val pureValue = value.replace(Regex("""["';]"""), "")
println("$key::$pureValue") // key::pqRjnA

Another version:

val (key, value) = document
    .select("script")
    .first { Regex("""key\s*=\s*["'].*["'];""") in it.data() }
    .data()
    .split("=")
    .map { it.replace(Regex("""[\s"';]"""), "") }
println("$key::$value") // key::pqRjnA

Footnote

To get the document you can do this:

  • From a file: 
    val input = File("my-document.html")
val document = Jsoup.parse(input, "UTF-8")
  • From a server: 
    val document = Jsoup.connect("the/target/url")
    .userAgent("Mozilla")
    .get()

Upvotes: 0

ollo
ollo

Reputation: 25350

Since jsoup isn't a javascript library you have two ways to solve this:

A. Use a javascript library

  • Pro:

    • Full Javascript support

  • Con:

    • Additional libraray / dependencies

B. Use Jsoup + manual parsing

  • Pro:

    • No extra libraries required
    • Enough for simple tasks

  • Con:

    • Not as flexible as a javascript library

Here's an example how to get the key with jsoupand some "manual" code:

Document doc = ...
Element script = doc.select("script").first(); // Get the script part


Pattern p = Pattern.compile("(?is)key=\"(.+?)\""); // Regex for the value of the key
Matcher m = p.matcher(script.html()); // you have to use html here and NOT text! Text will drop the 'key' part


while( m.find() )
{
    System.out.println(m.group()); // the whole key ('key = value')
    System.out.println(m.group(1)); // value only
}

Output (using your html part):

key="pqRjnA"
pqRjnA

Upvotes: 35

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