HtmlUnit Java Library Not Loading Expected Page Content

Other Questions Headless Browser
1

I’m using HtmlUnit for automating web tasks and I’m facing a problem where the page doesn’t update after I click a button. Here’s what I’m doing:

final WebClient browser = new WebClient(BrowserVersion.CHROME);
browser.getOptions().setJavaScriptEnabled(true);
browser.getOptions().setThrowExceptionOnScriptError(false);
browser.getOptions().setCssEnabled(true);
browser.getOptions().setUseInsecureSSL(true);
browser.getOptions().setRedirectEnabled(true);

HtmlPage currentPage = browser.getPage("https://example-ticketing-site.com/tickets/12345");

// Choose quantity from dropdown
HtmlSelect quantityDropdown = (HtmlSelect) currentPage.getElementById("ticket_quantity");
quantityDropdown.setSelectedAttribute("2", true);

// Press the purchase button
HtmlInput purchaseBtn = (HtmlInput) currentPage.getElementById("buy_tickets_btn");
HtmlPage resultPage = purchaseBtn.click();

Thread.sleep(30000);
System.out.println(resultPage.asText());

After I click the button and wait for a while, I still see the same page content. In a regular browser, it takes me to a verification page with a captcha. Why isn’t HtmlUnit performing as expected? Am I perhaps missing some settings or do I need to manage dynamic content loading differently?

2

yeah, it looks like the site might be blocking htmlunit since it thinks it’s a bot. try adding custom user agent headers like a real browser. also, ticketing sites do heavy js stuff, so switching to selenium webdriver could be a better option, just sayin.

3

This happens all the time with modern web apps. HtmlUnit just can’t handle sites that rely heavily on JavaScript, especially AJAX requests or DOM changes after button clicks. Even with JavaScript enabled, HtmlUnit’s engine is way weaker than real browsers. I’ve hit the same wall with ticketing platforms. These sites use anti-bot measures that fingerprint automated tools. Your sleep won’t work if content loads through async JavaScript calls that HtmlUnit can’t execute properly. Try browser.waitForBackgroundJavaScript() instead of Thread.sleep() - it lets pending JavaScript finish. But since you’re dealing with a ticketing site that probably has serious bot detection, you’ll likely need something more powerful like Selenium with an actual browser.

4

This happens all the time with ticketing sites. They’ve got detection systems that can spot HtmlUnit’s JavaScript engine, even with all browser options enabled. I’ve dealt with this before - the main issue is that HtmlUnit doesn’t handle complex JavaScript frameworks and async operations the same way real browsers do. These sites check for specific browser properties and behaviors that HtmlUnit just can’t fake properly. That captcha you’re seeing in regular browsers? It’s part of their anti-bot system designed to catch headless browsers like HtmlUnit. You could try better request headers, cookie management, and random delays to look more human, but honestly, these protected sites are tough to crack.