When to Use HtmlUnit

HtmlUnit is one of several libraries for working with web content. The right choice depends on your application's requirements.

HtmlUnit provides a browser-like programming model entirely within Java. It is often a good choice when JavaScript support is required, but running a full browser would be unnecessary or impractical.

The htmlunit-jsoup bridge combines HtmlUnit's browser emulation and JavaScript support with Jsoup's DOM and selector API. It also makes it possible to use many Jsoup-based libraries with pages loaded and rendered by HtmlUnit.

Finding form elements

For filling out a form, you first have to find the form elements you like to interact with.

final HtmlTextInput textField = form.getInputByName("userid");

In addition to all the general ways of finding dom elements (see below) the HtmlForm object offers some convenient methods to find form elements:

• HtmlForm.getButtonByName(String)
• HtmlForm.getButtonsByName(String)
• HtmlForm.getCheckedRadioButton(String)
• HtmlForm.getInputByName(String)
• HtmlForm.getInputByValue(String)
• HtmlForm.getInputsByName(String)
• HtmlForm.getInputsByValue(String)
• HtmlForm.getRadioButtonsByName(String)
• HtmlForm.getSelectByName(String)
• HtmlForm.getSelectsByName(String)
• HtmlForm.getTextAreaByName(String)
• HtmlForm.getTextAreasByName(String)
• HtmlForm.getElements()

All these methods are working based on a list of all dom elements associated with this form - this list includes all descendants of the form element AND all other elements associated to this form using the 'form' attribute. In general the method HtmlForm.getElements() builds this list and all other methods using this list as base for more filtering.

Text input <input type='text'>

These form elements represented as instances of class HtmlTextInput.

final HtmlTextInput textField = form.getInputByName("userid");

To replace the value with some new text you should use the method HtmlElement#type(String). This call takes care of setting the focus (if required; including triggering all the focus related events) and then simulating the typing of the provided string (char by char, including the keyboard events).

textField.type("RBRi");

If all the events not really needed, you can also use the method HtmlSelectableTextInput#setValue(String).

Text area <textarea>

These form elements represented as instances of class HtmlTextArea.

final HtmlTextArea textArea = form.getTextAreaByName("comment");

The usage of HtmlTextArea is similar to HtmlTextInput (because both derived from HtmlSelectableTextInput). This means you can also use type(String) or even setValue(String) for updating these elements.

textArea.type("HtmlUnit is a great library...");

Radio buttons <input type='radio'> and Checkboxes <input type='checkbox'>

These form elements represented as instances of class HtmlRadioButtonInput/HtmlCheckBoxInput.

final HtmlRadioButtonInput countryGermany = form.getInputByName("radio_country_germany");
final HtmlCheckBoxInput programmingLanguage = form.getInputByName("check_language_java");

Usually your form contains many of these elements organized in groups. To check a radio button of a checkbox you have to use HtmlRadioButtonInput#setChecked(boolean) or HtmlCheckBoxInput#setChecked(boolean).

countryGermany.setChecked(true);
programmingLanguage.setChecked(true);

Checking a single radio button will automatically uncheck all other radio buttons in the same group.

Select <select>

These form elements represented as instances of class HtmlSelect. The individual options are represented by instances of class HtmlOption.

final HtmlSelect currency = form.getInputByName("currency");
                <p>
                    The simplest way to select one of the options is the method
                    <a href='apidocs/org/htmlunit/html/HtmlSelect.html#setSelectedIndex-int-'>HtmlSelect.html#setSelectedIndex(int)</a>.
                </p>
                <source><![CDATA[
currency.setSelectedIndex(true);

To make your code more readable and robust, you have to search for the HtmlOption to select and then use HtmlSelect.html#setSelectedAttribute(HtmlOption, boolean).

HtmlOption euro = currency.getOptionByValue("Euro");
currency.setSelectedAttribute(euro, true);

For single selection select elements, this call also deselects all other options.

Traversing the DOM tree

Below is an example of finding a 'div' by an ID, and getting an anchor by name:

@Test
public void getElements() throws Exception {
    try (WebClient webClient = new WebClient()) {
        final HtmlPage page = webClient.getPage("http://some_url");

        final HtmlDivision div = page.getHtmlElementById("some_div_id");
        final HtmlAnchor anchor = page.getAnchorByName("anchor_name");
    }
}

A simple way for finding elements might be to find all elements of a specific type.

 @Test
 public void getElements() throws Exception {
    try (WebClient webClient = new WebClient()) {
        final HtmlPage page = webClient.getPage("http://some_url");

        final DomNodeList<DomElement> inputs = page.getElementsByTagName("input");
        final Iterator<DomElement> nodesIterator = inputs.iterator();
        // now iterate
    }
 }

There is rich set of methods usable to locate page elements e.g.

• HtmlPage.getAnchors(); HtmlPage.getAnchorByHref(String); HtmlPage.getAnchorByName(String); HtmlPage.getAnchorByText(String)
• HtmlPage.getElementById(String); HtmlPage.getElementsById(String); HtmlPage.getElementsByIdAndOrName(String);
• HtmlPage.getElementByName(String); HtmlPage.getElementsByName(String)
• HtmlPage.getFormByName(String); HtmlPage.getForms()
• HtmlPage.getFrameByName(String); HtmlPage.getFrames()

You can also start searching from the document element (HtmlPage.getDocumentElement()) and then traverse the dom tree

• HtmlElement.getElementsByAttribute(String, String, String)
• DomElement.getElementsByTagName(String); DomElement.getElementsByTagNameNS(String, String)
• DomElement.getChildElements(); DomElement.getChildElementCount()
• DomElement.getFirstElementChild(); DomElement.getLastElementChild()
• HtmlElement.getEnclosingElement(String); HtmlElement.getEnclosingForm()
• DomNode.getChildNodes(); DomNode.getChildren(); DomNode.getDescendants(); DomNode.getDomElementDescendants(); DomNode.getFirstChild(); DomNode.getHtmlElementDescendants() DomNode.getLastChild(); DomNode.getNextElementSibling(); DomNode.getNextSibling(); DomNode.getPreviousElementSibling(); getPreviousSibling()

CSS Selectors

You can also use CSS selectors

@Test
public void cssSelector() throws Exception {
    try (WebClient webClient = new WebClient()) {
        final HtmlPage page = webClient.getPage("https://www.htmlunit.org/");

        //get list of all divs
        final DomNodeList<DomNode> divs = page.querySelectorAll("div");
        for (final DomNode div : divs) {
            // ....
        }

        //get div which has the id 'breadcrumbs'
        final DomNode div = page.querySelector("div#breadcrumbs");
    }
}

XPath queries

XPath is the suggested way for more complex searches, a brief tutorial can be found in W3Schools

@Test
public void xpath() throws Exception {
    try (WebClient webClient = new WebClient()) {
        final HtmlPage page = webClient.getPage("https://www.htmlunit.org/");

        //get list of all divs
        final List<?> divs = page.getByXPath("//div");

        //get div which has a 'id' attribute of 'banner'
        final HtmlDivision div = (HtmlDivision) page.getByXPath("//div[@id='banner']").get(0);
    }
}

Extracting the whole page content

If you want to extract all text from an entire page without targeting specific elements, you can call asNormalizedText() directly on the body element. This is useful for getting a quick overview of all visible content or for full-text indexing.
Here's a simple example that loads a page and extracts all its text:

@Test
public void extractTextFromBody() throws Exception {
    try (WebClient webClient = new WebClient()) {
        final HtmlPage page = webClient.getPage("https://www.htmlunit.org/");

        final HtmlBody body = page.getBody();

        // A normalized textual representation of this element that represents
        // what would be visible to the user if this page was shown in a web browser.
        // Whitespace is normalized like in the browser and block tags are separated by '\n'.
        final String bodyContent = body.asNormalizedText();
    }
}