# install latest Java Development Kit (JDK) # install selenium standalone server, current beta # open Terminal, navigate to folder where standalone server file is deposited # check whether processes run on port 4444 with lsof -i:4444; potentially kill them using PID # run the following line in Terminal: java -jar selenium-server-standalone-3.0. Web scraping using Selenium and BeautifulSoup can be a handy tool in your bag of Python and data knowledge tricks, especially when you face dynamic pages and heavy JavaScript-rendered websites. This guide has covered only some aspects of Selenium and web scraping.
With the help of Selenium, we can also scrap the data from the webpages. Here, In this article, we are going to discuss how to scrap multiple pages using selenium. There can be many ways for scraping the data from webpages, we will discuss one of them. Looping over the page number is the most simple way for scraping the data.
JSoup
JSoup is a HTML parser, it can't control the web page, only parse the content. Supports only CSS Selectors. It gives you the possibility to select elements using jQuery-like CSS selectors and provides a slick API to traverse the HTML DOM tree to get the elements of interest. Particularly the traversing of the HTML DOM tree is the major strength of JSoup. Can be used in web applications.
HtmlUnit
HtmlUnit is a 'GUI-Less browser for Java programs'. The HtmlUnit browser can simulate Chrome, Firefox or Internet Explorer behaviour. It is a light weight solution that doesn't have too many dependencies. Generally, it supports JavaScript and Cookies, but in some cases it may fail. HtmlUnit is used for testing, web scraping, and is the basis for other tools.You can simulate pretty much anything a browser can do like click events, submit events etc. It's much more than alone a HTML parser, is ideal for web application automated unit testing. Supports XPath, but the problem starts when you try to extract structured data from modern web applications that use JQuery and other Ajax features and use Div tags extensively. HtmlUnit and other XPath based html parsers will not work well with web applications. There is a little project on github available that extends HtmlUnit to support CSS resp. limited jQuery querying.
HTMLUnitDriver
HTML unit driver is the most light weight and fastest implementation headless browser of WebDriver. It is based on HtmlUnit.
Jaunt
Is similar to JSoup, and includes integrated working with REST APIs and JSON. It's fast but it doesn't support JavaScript. Is a commercial library.
ui4j
Ui4j is a web-automation library for Java. It is a thin wrapper library around the JavaFx WebKit Engine (including headless modes), and can be used for automating the use of web pages and for testing web pages. Pure Java 8 solution.
Selenium
Is a suite of tools to automate web browsers across many platforms. Nevertheless, it could be used for web scraping. Is composed of several components with each taking on a specific role in aiding the development of web application test automation.
Selenium WebDriver
A collection of language specific bindings to drive a browser.
Remote WebDriver
Separates where the tests are running from where the browser is. Allows tests to be run with browsers not available on the current OS (because the browser can be elsewhere). Can be used in the same that webdriver, the primary difference is that remote webdriver needs to be configured so that it can run the tests on a seperate machine. The RemoteWebDriver is composed of two pieces: a client and a server.
PhantomJS
Headless browser used for automating web page interaction. It provides a JavaScript API enabling automated navigation, screenshots, user behavior and assertions making it a common tool used to run browser-based unit tests in a headless system like a continuous integration environment. Based on WebKit.
Web Scraping Using Selenium Python
PhantomJSDriver (or Ghostdriver)
Project that provides Selenium WebDriver bindings for Java. It controls a PhantomJS running in Remote WebDriver mode. In order to use PhantomJS with Seleniun, one has to use GhostDriver.
Sources:
https://dzone.com/articles/htmlunit-vs-jsoup-html-parsing
https://www.innoq.com/en/blog/webscraping/
http://stackoverflow.com/questions/3152138/what-are-the-pros-and-cons-of-the-leading-java-html-parsers
http://mph-web.de/web-scraping-jaunt-vs-jsoup/
http://stackoverflow.com/questions/814757/headless-internet-browser
https://seleniumhq.github.io/docs/remote.html
http://www.assertselenium.com/headless-testing/getting-started-with-ghostdriver-phantomjs/
http://www.guru99.com/selenium-with-htmlunit-driver-phantomjs.html
http://stackoverflow.com/questions/28008825/htmlunitdriver-htmlunit-vs-ghostdriver-phantomjs
Python Web Scraping With Selenium Java
In this article I will show you how it iseasy to scrape a web siteusingSelenium WebDriver. I will guide you through a sample project which is written inC#and usesWebDriverin conjunction with theChromebrowser to login on thetesting pageand scrape the text from the private area of the website.
Downloading the WebDriver
First of all we need to get the latest version ofSelenium Client & WebDriver Language Bindings and theChrome Driver. Of course, you can download WebDriver bindings for any language (Java, C#, Python, Ruby), but within the scope of this sample project I will use the C# binding only. Ahnlab safe transaction what is it. In the same manner, you can use any browser driver, but here I will use Chrome.
After downloading the libraries and the browser driver we need to include them in our Visual Studio solution:
Creating the scraping program
In order to use the WebDriver in our program we need to add its namespaces:
Then, in the main function, we need to initialize the Chrome Driver:
This piece of code searches for thechromedriver.exefile. If this file is located in a directory different from the directory where our program is executed, then we need to specify explicitly its path in theChromeDriverconstructor.
When an instance of ChromeDriver is created, a new Chrome browser will be started. Now we can control this browser via thedrivervariable. Let’s navigate to the target URL first:
Then we can find the web page elements needed for us to login in the private area of the website:
Here we search for user name and password fields and the login button and put them into the corresponding variables. After we have found them, we can type in the user name and the password and press the login button:
Web Scraping With Selenium Java
At this point the new page will be loaded into the browser, and after it’s done we can scrape the text we need and save it into the file:
That’s it! At the end, I’d like to give you a bonus – saving a screenshot of the current page into a file:
The complete program listing
Get the whole project.
What Is Web Scraping
Conclusion
Web Scraping Python Selenium Javascript
I hope you are impressed with how easy it is to scrape web pages using the WebDriver. You can naturally press keys and click buttons as you would in working with the browser. You don’t even need to understand what kind of HTTP requests are sent and what cookies are stored; the browser does all this for you. This makes theWebDrivera wonderful tool in the hands of a web scraping specialist.