6. Use DOM methods to navigate a document

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Use DOM methods to navigate a document

Problem

You have a HTML document that you want to extract data from. You know generally the structure of the HTML document.

Solution

Use the DOM-like methods available after parsing HTML into a Document.

File input = new File("/tmp/input.html"); 
Document doc = Jsoup.parse(input, "UTF-8", "http://example.com/"); 
Element content = doc.getElementById("content"); 
Elements links = content.getElementsByTag("a");for (Element link : links) { 
  String linkHref = link.attr("href");  String linkText = link.text();}

Description

Elements provide a range of DOM-like methods to find elements, and extract and manipulate their data. The DOM getters are contextual: called on a parent Document they find matching elements under the document; called on a child element they find elements under that child. In this way you can winnow in on the data you want.

Finding elements

getElementById(String id)
getElementsByTag(String tag)
getElementsByClass(String className)
getElementsByAttribute(String key) (and related methods)
Element siblings: siblingElements(), firstElementSibling(), lastElementSibling(); nextElementSibling(), previousElementSibling()
Graph: parent(), children(), child(int index)

Element data

attr(String key) to get and attr(String key, String value) to set attributes
attributes() to get all attributes
id(), className() and classNames()
text() to get and text(String value) to set the text content
html() to get and html(String value) to set the inner HTML content
outerHtml() to get the outer HTML value
data() to get data content (e.g. of script and style tags)
tag() and tagName()

Manipulating HTML and text

append(String html), prepend(String html)
appendText(String text), prependText(String text)
appendElement(String tagName), prependElement(String tagName)
html(String value)

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