8 Most Popular Java Web Crawling & Scraping Libraries
Article originally posted on Data Science Central. Visit Data Science Central
Introduction :
Web scraping or crawling is the process of extracting data from any website. The data does not necessarily have to be in the form of text, it could be images, tables, audio or video. It requires downloading and parsing the HTML code in order to scrape the data that you require.
Since data is growing at a fast clip on the web, it is not possible to manually copy and paste it. At times, it is not possible for technical reasons. In any case, web scraping and crawling enables this process of fetching the data in an easy and automated fashion. As it is automated, there’s no upper limit to how much data you can extract. In other words, you can extract large quantities of data from disparate sources.
Data has always been important but of late, businesses have begun to use data in order to make business decisions. As businesses rely heavily on data for decision making, web scraping has, in turn, grown in significance. However, as data needs to be collated from different sources, it is even more important to leverage web scraping as it can make this entire exercise quite easy and hassle-free.
As information is scattered all over the digital space in the form of news, social media posts, images on Instagram, articles, e-commerce sites etc., web scraping is the most efficient way to keep an eye on the big picture and derive business insights that can propel your enterprise. In this context, java web scraping/crawling libraries can come in quite handy. Here’s a list of best java web scraping/crawling libraries which can help you to crawl and scrape the data you want from the Internet.
1. Apache Nutch
Apache Nutch is one of the most efficient and popular open source web crawler software projects. It’s great to use because it offers varied extensible interfaces such as Parse, Index and Scoring Filter’s custom implementations such as Apache Tika for parsing. Moreover, it is also possible to use pluggable indexing for Apache Solr, Elastic Search etc.
Scrapy is technically not even a library it’s a complete web scraping framework. That means you can use it to manage requests, preserve user sessions, follow redirects, and handle output pipelines. It also means you can swap out individual modules with other Python web scraping libraries. Web Scraping Frameworks These are complete web scraping toolsets that cover every part of the journey: scraping, parsing, and then storing the data in a format of your choice. Scrapy – a full-fledged web crawling and scraping framework for complex projects. Web Scraping Web scraping is commonly used as a means to collect and analyze data available on the web. In recent years, several web scraping frameworks have been released to help in this process and serve specific use cases as well. In this article, we will cover a list of leading open source scraping solutions apart from Scrapy. Pyspider is another web scraping framework written for python programmers to develop web scrapers. Pyspider is a powerful web crawling framework you can use to create web scrapers for the modern web. Unlike in the case of Scrapy that does not render JavaScripts on its.
Pros:
- Highly scalable and relatively feature rich crawler.
- Features like politeness, which obeys robots.txt rules.
- Robust and scalable – Nutch can run on a cluster of up to 100 machines.
Resources:
- Learn More:Apache Nutch – Step by Step
2. StormCrawler
StormCrawler stands out as it serves a library and collection of resources that developers can use for building their own crawlers. StormCrawler is also preferred by many for use cases in which the URL to fetch and parse come as streams. However, you can also use it for large scale recursive crawls particularly where low latency is needed.
Pros:
- scalable
- resilient
- low latency
- easy to extend
- polite yet efficient
Resources:
- Learn More:Getting Started with StormCrawler
3. Jsoup
jsoupis great as a Java library which helps you navigate the real-world HTML. Developers love it because offers quite a convenient API for extracting and manipulating data, making use of the best of DOM, CSS and jquery-like methods.
Pros:
- Fully supports CSS selectors
- Sanitize HTML
- Built-in proxy support
- Provides a slick API to traverse the HTML DOM tree to get the elements of interest.
Resources:
- Learn More:Jsoup HTML parser – Tutorial & examples
4. Jaunt
Jauntis a unique Java library that helps you in processes pertaining to web scraping, web automation and JSON querying. When it comes to a browser, it does provide web scraping functionality, access to DOM, and control over each HTTP Request/Response but does not support JavaScript. Since Jaunt is a commercial library, it offers diverse kinds of versions, paid as well as free for a monthly download.
Pros:
- The library provides a fast, ultra-light headless browser
- Web pagination discovery
- Customizable caching & content handlers
Resources :
- Learn More:Jaunt Web Scraping Tutorial – Quickstart
5. Norconex HTTP Collector
If you are looking for open source web crawlers related to enterprise needs, Norconex is what you need.
Norconexis a great tool because it enables you to crawl any kind of web content that you need. You can use it as you wish- as a full-featured collector or embed it in your own application. Moreover, it works well on any operating system. It can crawl millions of pages on a single server of median capacity.
Pros:
- Highly scalable – Can crawl millions on a single server of average capacity
- OCR support on images and PDFs
- Configurable crawling speed
- Language detection
Resources:
- DownloadNorconex HTTP Collector
- Learn More:Getting Started with Norconex HTTP Collector
6. WebSPHINX
WebSPHINX(Website-Specific Processors for HTML INformation eXtraction) is an excellent tool as a Java class library and interactive development environment for web crawlers. WebSPHINX comprises two main parts: the Crawler Workbench and the WebSPHINX class library.
Web Scraping Frameworks Pdf
Pros:
- Provide a graphical user interface that lets you configure and control a customizable web crawler
Resources:
- Learn More:Crawling web pages with WebSPHINX
7. HtmlUnit
HtmlUnitis a headless web browser written in Java.
It’s a great tool because it allows high-level manipulation of websites from other Java code, including filling and submitting forms and clicking hyperlinks.
It has also got considerable JavaScript support which continues to improve. It is also equipped to work even with the most complex AJAX libraries, simulating Chrome, Firefox or Internet Explorer depending on the configuration used. It is mostly made use of when it comes to testing purposes in order to fetch information from websites.
Pros:
- Provides high-level API, taking away lower-level details away from the user.
- It can be configured to simulate a specific Browser.
Resources:
- Learn More:Web Scraping with Java and HtmlUnit
8. Gecco
Geccois also a hassle-free lightweight web crawler developed with Java language. Gecco framework is preferred for its remarkable scalability. The framework is based on the principle of open and close design, the provision to modify the closure and the expansion of open.
Pros:
- Support for asynchronous Ajax requests in the page
- Support the download proxy server randomly selected
- Using Redis to realize distributed crawling
Resources:
- Learn More:Teach you to use java crawler gecco to grab all JD product information (1)
Conclusion :
As the applications of web scraping grow, the use of Java web scraping libraries is also set to accelerate. Since there are various libraries, and each one has its own unique features, it will require some study on the part of the end user. However, it will also depend on the respective needs of different end users which will determine which tool would suit better. Once the needs are clear, it would be possible to leverage these tools and power your web scraping endeavours in order to gain a competitive advantage!
Web Scraping Libraries R
Subscribe for MMS Newsletter
By signing up, you will receive updates about our latest information.
Did you know...
Open Source Web Crawler
More than half of fortune 500 companies are planning an AI project in the next 6 months!
(Subscribe to be in the know!)