import java.io.IOException; import java.net.URL; import java.util.HashSet; import java.util.Set; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; class WebCrawler implements Runnable { private String url; private Set visitedUrls; public WebCrawler(String url, Set visitedUrls) { this.url = url; this.visitedUrls = visitedUrls; } @Override public void run() { // Fetch web page and perform crawling logic crawl(url); } private void crawl(String url) { // Add the URL to the set of visited URLs visitedUrls.add(url); try { // Fetch the web page content // Implement your own logic here to fetch the web page content String webPageContent = fetchWebPageContent(url); // Process the web page content // Implement your own logic here to process the web page content processWebPageContent(webPageContent); // Extract links from the web page // Implement your own logic here to extract links from the web page Set links = extractLinks(webPageContent); // Create new web crawler threads for unvisited links ExecutorService executorService = Executors.newFixedThreadPool(5); for (String link : links) { if (!visitedUrls.contains(link)) { executorService.execute(new WebCrawler(link, visitedUrls)); } } // Shutdown the executor service executorService.shutdown(); } catch (IOException e) { System.out.println("Error fetching web page: " + url); } } private String fetchWebPageContent(String url) throws IOException { // Implement your own logic here to fetch the web page content // You can use libraries like Jsoup for web scraping // Dummy implementation to simulate fetching web page content return "Example"; } private void processWebPageContent(String webPageContent) { // Implement your own logic here to process the web page content // You can parse the HTML, extract information, etc. } private Set extractLinks(String webPageContent) { // Implement your own logic here to extract links from the web page // You can use libraries like Jsoup for HTML parsing // Dummy implementation to simulate extracting links Set links = new HashSet<>(); links.add("https://example.com/page1"); links.add("https://example.com/page2"); return links; } } public class thread6 { public static void main(String[] args) { String startingUrl = "https://example.com"; Set visitedUrls = new HashSet<>(); // Create a web crawler thread for the starting URL WebCrawler webCrawler = new WebCrawler(startingUrl, visitedUrls); // Create a new thread and start crawling Thread crawlerThread = new Thread(webCrawler); crawlerThread.start(); } }