#Chrome web scraper tutorial how to
#Chrome web scraper tutorial code

No matter what, don’t give up! With a little troubleshooting, you should be able to get the data you need. Sometimes, they may be willing to whitelist your IP address so that you can access the data. If you’re still having trouble, you can try reaching out to the website directly and asking them why they’re blocking Java. These languages are not as commonly blocked by websites.

This will allow you to access the website without it knowing that you’re using Java.Īnother way to get around this issue is to use a different web scraping tool, like Python or Ruby. There are a few ways to get around this issue. If the website doesn’t load, or you can’t access the data you want, then the website is most likely blocking Java. To check if this is the case, try opening the website in a different browser, like Chrome or Firefox.

#Chrome web scraper tutorial code

If the code is correct, but you’re still not getting the data you want, it could be because the website you’re scraping is blocking Java.

#Chrome web scraper tutorial how to

If you’re not sure how to do this, you can use a web scraping tool like Fiddler or Wireshark to check the code. Make sure that it is correctly pulling the data from the website. It probably doesn't have any data at all.If you’re web scraping with Java, and you’re having trouble getting the data you want, there are a few things you can do to troubleshoot the issues.įirst, check the code that you’re using to scrape the data. queue, it calls immidietely, however your urlsToVisit is not complete yet.

another is to go thru the collected links.one is to go thru the target page and collect links,.Problem: Wrong logic on continuous crawling Click the Grepsr icon next to the address bar (the blue ‘g’) to activate the extension. On your web browser (Google Chrome and Microsoft Edge supported for now), go to the web page from where you want to extract the data. The map function does not use link, you are pushing same data over and over to the urlsToVisit Web Scraping Tutorial for Grepsr’s Browser Extension.You mentioned, however result has links, so the path should be result.links instead.There are multiple problems with your code. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with. (node:4909) UnhandledPromiseRejectionWarning: Unhandled promise rejection. (/home/ubuntu/workspace/node_modules/headless-chrome-crawler/lib/helper.js:177:23)Īt HCCrawler._request (/home/ubuntu/workspace/node_modules/headless-chrome-crawler/lib/hccrawler.js:349:21) Most likely the page has been closed.Īt assert (/home/ubuntu/workspace/node_modules/headless-chrome-crawler/node_modules/puppeteer/lib/helper.js:251:11)Īt Page.close (/home/ubuntu/workspace/node_modules/headless-chrome-crawler/node_modules/puppeteer/lib/Page.js:883:5)Īt Crawler.close (/home/ubuntu/workspace/node_modules/headless-chrome-crawler/lib/crawler.js:80:22)Īt Crawler. (node:4909) UnhandledPromiseRejectionWarning: Error: Protocol error: Connection closed. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code. (node:4909) DeprecationWarning: Unhandled promise rejections are deprecated. (/home/ubuntu/workspace/node_modules/headless-chrome-crawler/lib/helper.js:177:23)Īt /home/ubuntu/workspace/crawlertop.js:30:17Īt process._tickCallback (internal/process/next_tick.js:118:7) Received type objectĪt (/home/ubuntu/workspace/node_modules/headless-chrome-crawler/lib/hccrawler.js:167:27)Īt arrayMap (/home/ubuntu/workspace/node_modules/headless-chrome-crawler/node_modules/lodash/_arrayMap.js:16:21)Īt map (/home/ubuntu/workspace/node_modules/headless-chrome-crawler/node_modules/lodash/map.js:50:10)Īt HCCrawler.queue (/home/ubuntu/workspace/node_modules/headless-chrome-crawler/lib/hccrawler.js:157:23)Īt HCCrawler. My logs: (node:4909) UnhandledPromiseRejectionWarning: TypeError : The 'url' argument must be of type string.

Function to be called with evaluated results from browsersĪwait crawler.onIdle() // Resolved when no queue is leftĪwait crawler.close() // Close the crawler This is my code now: const HCCrawler = require('headless-chrome-crawler') I want to get all links from a page and pass them into an array list to crawl them. However, i found some troubles tryng crawl a entire website using this awesome package. So i discovered HeadLess Chrome Crawler, a good node package. I've been studying chrome puppeteer to develop a crawler for learning purposes.