Using Proxies with Java Web Scraping:AGuide
While the 20th century was all about time being money, the current digital era is more inclined to data being money Besides, do you know what’s common between a CEO of a multinational company, an entrepreneur, and a marketer? Well, they all gain valuable insights using data collected from different sources and strategize their action plans.
Data is now a pivotal differentiator that is the core of business strategies and market research for every industry.
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to Know
No doubt we are accelerating our transformation to a data driven world Data collection using web scraping has increasingly become an integral part of several organizations as it provides a fast, flexible, and inexpensive way to gather data over the internet
But what is web scraping? Why should you use Java Web Scraping code for an application? Most importantly, when we can collect data through web scraping, what do we need proxies for?
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To help you out, here is the breakdown of everything you will need to know about scraping and proxies
Understanding Web Scraping and Proxies
Web scraping refers to the process of collecting data and other content information from a website over the internet Simply put, web scraping is the technique of extracting data from the internet All the collected data is then exported in the API, CSV, or spreadsheet format whichever is more convenient for the user to understand.
Read: Data-Oriented Programming in Java
Previously, individuals used to copy and paste the required information manually, but it is not an effective way, especially if they want data from a large and complex website.
With web scraping, the data extraction process gets automated, making it easier to extract data from any web page regardless of the size and type of data. Some of the Web Scraping applications include competitive analysis, fetching images and product descriptions, aggregating new articles, extracting financial statements, predictive analysis, real-time analytics, machine learning training models, data driven marketing, lead generation, content marketing, SEO monitoring, and monitoring sentiments of customers
But web scraping also has some limitations For instance, you may not face any problems if you are scraping a small website, but trying to fetch data from a large scale website or search engine like Google your requests can be blocked either due to IPrate limitations or IP Geolocation
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And that’s where proxies come to your rescue.
Proxies are like middlemen residing between the client and the website server They are used for disguising the client-side IPaddress and optimizing connection routes.To avoid IPblocking while web scraping, proxies are used to cloak or change their IPs and create anonymity Some of the proxies that can be used are transparent proxy, high anonymity proxy, distorting proxy, data center proxy, residential proxy, public proxy, private proxy, shared proxy, dedicated proxy, mobile proxy, SSLproxy, rotating proxy, and reverse proxy
But, it still doesn’t answer where Java fits in all this, right?
Don’t fret! We will help you understand in the next section.
Using jsoup for Web Scraping
Being the oldest yet most popular language, Java allows the creation of highly reliable and scalable services as well as data extraction solutions (multi threaded) using its libraries like HTMLUnit, Jaunt, or jsoup.
In this blog, we will cover how jsoup can help you with web scraping,
at what it is jsoup, an open source Java library, is used to parse, manipulate, and extract data from JSON data payloads or HTML pages through a headless browser Some capabilities of jsoup include ● Searching and extracting data through CSS selectors or DOM traversal ● Immaculate user content to avoid Cross Site Scripting (XSS) attacks ● HTMLis scraped and parsed from files, URLs, and strings. ● Manipulating attributes, elements, and texts in HTML ● HTMLtidy output To use jsoup for web scraping, download the jsoup jar file and add the jsoup library to the project. If you use Gradle to manage Java project dependencies, you can implement jsoup as follows: // jsoup HTML parser library @ https://jsoup.org/ implementation 'org.jsoup:jsoup:1.15.3' While using Maven, you won’t have to download the jar file rather you can add it in the dependencies of project object model section as follows: <dependency> <!-- jsoup HTML parser library @ https://jsoup.org/ --> <groupId>org.jsoup</groupId> <artifactId>jsoup</artifactId> <version>1.15.3</version> </dependency> What makes jsoup a great choice is it is self-contained hence there are no dependencies for runtime It not only runs on Java 8 and up but also on Kotlin, Scala, GoogleApp Engine, Lambda, and OSGi Moreover, if you want to create some changes, you will need to build a jar from the source in GITto stay updated or reverse your changes To do that, run the integration and unit test and install a snapshot jar into the Maven repository as follows: git clone https://github.com/jhy/jsoup.git cd jsoup mvn install
but first, let’s take a brief look
Then parse the HTMLpage to extract in your Java code as: //Pass Input Argument (URL) try { Document page= Jsoup.connect("https://www.decipherzone.com/").get(); } }catch (IOException e){ e.getMessage(); } To extract data with jsoup, you can either use DOM methods like getElementsByAttribute(String key),getElementsByClass(String className), or Sibling Elements: siblingElements(), firstElementSibling(), lastElementSibling(); nextElementSibling(),
or selector syntax. You can extract data from different sites for eCommerce price comparison and monitoring,
mining, web indexing, market research,
sales
more In the above mentioned code, jsoup loads and parses HTMLcontent into
connects the method to the URLof the page, and
get method retrieves
data How to Use Proxies in your Java Web Scraping Software? If you want to add a proxy to jsoup web scraping and avoid getting your IPaddress blocked, then you will have to add the proxy server details prior to connecting to the URL For that, you need to use the System class’setProperty method and define the property of the proxy For example, you can set the proxy as follows: //set HTTP proxy host to 123.21.4.23 System.setProperty("http.proxyHost", "123.21.4.23"); //set HTTP proxy port to 2000 System.setProperty("http.proxyPort", "2000"); And in case, you need to authenticate the proxy server requires then define it this way: System.setProperty("http.proxyUser", "<insert username>"); System.setProperty("http.proxyPassword", "<insert password>");
previousElementSibling()
data
social listening, collecting
leads, market research, and
an object, Jsoup class
the
the web page
