We looked at the functionalities of both Jsoup and Ui4j. In this blog, we saw what web scraping is, some of the common libraries used for web scraping in Java, and how to use them. There are a lot more examples given in the GitHub page of Ui4j, go here, if you want to take a look at them. We can execute scripts by running the executeScript() method from an object of the Page class. For example, instead of using the setValue() method to enter the value into the search bar, we could have executed a simple JavaScript code that does that. When you create a Page instance, use the show() method This will open up a headless browser and you can see if you are on the right track, in terms of form filling etc.Also, we can type custom JavaScript and do things faster, without needing to code much with Java. Two things that Ui4j can do that really impressed me were its ability to display currently being scraped and its support for executing custom user defined JavaScript. If you are interested in the different user agents out there, take a look at this 4. When all this is done in succession, the url of page would have changed to the new one, containing the results of searching “ui4j” Now, since there isn’t a button to simulate a click, we have to use Java’s Robot class, to simulate pressing the enter key. This is basically the same thing as typing “ui4j” into the search bar. I query for an input tag with the value q and I set its value as “ui4j”. Now when we navigate to the page using this configuration, it makes it easy for us to scrape because Google can’t distinguish us between a bot and a real browser. I took advantage of Ui4j’s PageConfiguration to set the user agent of our browser to mimic a Chrome Browser running on Windows 10. So, I had to add a few extra lines of code to trick it into thinking that our program was an actual browser. Google is pretty smart when it comes to preventing bots. navigate ( "", config ) Document doc = page. setUserAgent ( "Mozilla/5.0 (Windows NT 10.0 Win64 圆4)AppleWebKit/537.36(KHTML, like Gecko)Chrome/.87Safari/537.36" ) Page page = browser. getWebKit () PageConfiguration config = new PageConfiguration () config. Getting the HTMLīrowserEngine browser = BrowserFactory. Similar to Jsoup, you have to add the jar file to the build path before coding. We can use this to automate navigating of web pages, meaning, we can simulate clicks, fill forms and a lot more. It may not be as light weight as Jsoup that is because it is basically a browser. Ui4j is a library built on the JavaFX WebKit Engine. Now let’s take a look at one of my favorite scraping libraries. If you are interested in the other features that Jsoup provides, you can take a look at its documentation. The topics mentioned above barely scratch the surface of the things Jsoup can do. This should be enough to get you started with Jsoup. These were just a few examples of stuff you can extract. You can get other information like the id name, class name, tagname etc. Here, we use some of the methods that help us getting information like the text within a tag, outer and inner HTML. select ( "a" ) for ( Element link: links ) Getting the html content of a websiteĭocument doc = Jsoup. Use google if you aren’t sure how to do that. This should give you a good idea of using Jsoup efficiently.īefore getting started, you should add the Jsoup jar file to the build path. I’ll be going into the basics of using Jsoup, like getting the HTML content of a website, getting an element by its ID, etc. Jsoup is one of the go-to libraries when it comes to parsing HTML, it’s easy to use, flexible, and it has a lot of tricks up its sleeves. In HTML, you need to know what type of tags there are, what attributes are etc. On the Java side, you need to be familiar with the common functions, the architecture of a class etc. You need to know the basics of Java, as well as a bit of HTML. Jokes aside, it has lots of amazing libraries out there which makes it easy to scrape with. There are a lot of ways you can scrape the web I prefer to do it with Java because, well, it’s the best language out there, period. What if you could write a few lines of code and get all the information you need delivered to you instantly? Web scraping paves the way for a person to get what they want, when they want, from any website. Everyday a lot of time is wasted when you visit the same website again and again for getting information.
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