It will be an "authenticated" screenshot, so we will need to have a username and password and provide those to the sign-in dialogue.įor starters, we need to get an instance of a WebDriver object (as we are using Chrome, this will be ChromeDriver for the implementation), in order to be able to access the browser in the first place. a ChromeDriver binary matching your Chrome versionĪ screenshot, we said, right? But to make things a tad more interesting, it will be a screenshot with a twist.So without further ado, here the list of packages you will need to run our code examples. Before we can jump right into coding and making our browser do our bidding, we first need to make sure we have the right environment and all the necessary tools.Īs for the browser, the library we are going to use (spoiler, Selenium) actually supports a number of different browsers, though for our examples here we will focus on Chrome, but it should be easy to just switch the driver for a different browser engine. We will start with something simple and try to get a screenshot of Hacker News in our first example. Your favourite browser engine is at your fingertips, only a couple of Java commands away.Īll right, we have now marvelled long enough at the theory, time to get into coding. No more issues with only partially supported CSS features, possibly slightly incompatible JavaScript code, or performance bottlenecks with overly complex HTML pages. It allows you to have the same kind of control and automation, you were used to with HtmlUnit and PhantomJS, but this time in the context of the very same browser engine you are using every day yourself, and which you are most likely using right now to read this article. Headless mode in Chrome has proven to be quite use- and powerful. Then, in 2017, there was a real game changer in this field, when both, Google and Mozilla, started to natively support a feature called headless mode in their respective browsers. Nonetheless, there occasionally were issues, either with performance or with support of web standards. HtmlUnit for scraping basic sites and PhantomJS for scraping dynamic sites which make heavy use of JavaScript.īoth are tremendous tools and there's a reason why PhantomJS happened to be the leader in that market for a long time. In previous articles, we talked about two different approaches to perform basic web scraping with Java.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |