HtmlUnit

HtmlUnit is a "GUI-Less browser for Java programs". It models HTML documents and provides an API that allows you to invoke pages, fill out forms, click links, etc... just like you do in your "normal" browser.

It has fairly good JavaScript support (which is constantly improving) and is able to work even with quite complex AJAX libraries, simulating either Firefox or Internet Explorer depending on the configuration you want to use.

It is typically used for testing purposes or to retrieve information from web sites.

HtmlUnit is not a generic unit testing framework. It is specifically a way to simulate a browser for testing purposes and is intended to be used within another testing framework such as JUnit or TestNG. Refer to the document "Getting Started with HtmlUnit" for an introduction.

HtmlUnit is used as the underlying "browser" by different Open Source tools like Canoo WebTest, JWebUnit, WebDriver, JSFUnit, WETATOR, Celerity, ...

HtmlUnit was originally written by Mike Bowler of Gargoyle Software and is released under the Apache 2 license. Since then, it has received many contributions from other developers, and would not be where it is today without their assistance.

Features

  • Support for the HTTP and HTTPS protocols
  • Support for cookies
  • Ability to specify whether failing responses from the server should throw exceptions or should be returned as pages of the appropriate type (based on content type)
  • Support for submit methods POST and GET (as well as HEAD, DELETE, ...)
  • Ability to customize the request headers being sent to the server
  • Support for HTML responses
    • Wrapper for HTML pages that provides easy access to all information contained inside them
    • Support for submitting forms
    • Support for clicking links
    • Support for walking the DOM model of the HTML document
  • Proxy server support
  • Support for basic and NTLM authentication
  • Excellent JavaScript support (see the JavaScript section below)

Installation

Place all the required jars in your classpath. All of these can be found in the lib directory of the HtmlUnit installation.

JavaScript Support

HtmlUnit provides excellent JavaScript support, simulating the behavior of the configured browser (Firefox or Internet Explorer). It uses the Rhino JavaScript engine for the core language (plus workarounds for some Rhino bugs) and provides the implementation for the objects specific to execution in a browser.

The unit tests of some well-known JavaScript libraries are included in HtmlUnit's own unit tests; based on these unit tests, the following libraries are known to work well with HtmlUnit:

  • jQuery 1.2.6: Full support (see unit test here)
  • MochiKit 1.4.1: Full support (see unit tests here)
  • GWT 2.5.0: Full support (see unit test here)
  • Sarissa 0.9.9.3: Full support (see unit test here)
  • MooTools 1.2.1: Full support (see unit test here)
  • Prototype 1.6.0: Very good support (see unit test here)
  • Ext JS 2.2: Very good support (see unit test here)
  • Dojo 1.0.2: Good support (see unit test here)
  • YUI 2.3.0: Good support (see unit test here)

To disable JavaScript processing for one WebClient, call webClient.getOptions().setJavaScriptEnabled(false).

JavaScript code is executed just like in normal browsers when the page loads or when an handler is triggered. Additionally HtmlUnit provides the ability to inject code into an existing page via HtmlPage.executeJavascript(String yourJsCode).

Refer to the changes document for details on what is being added.