1. import java.io.BufferedReader;
  2. import java.io.FileReader;
  3. import java.io.IOException;
  4. import java.util.HashMap;
  5. import java.util.Map;
  7. public class HtmlCache {
  9. private final Map<String, String> cache = new HashMap<>(); // Cache to store HTML content
  10. private final int cacheSizeLimit; // Maximum number of HTML documents to cache
  12. public HtmlCache(int cacheSizeLimit) {
  13. this.cacheSizeLimit = cacheSizeLimit;
  14. }
  16. /**
  17. * Retrieves the HTML content for a given URL from the cache.
  18. * If the content is not in the cache, it fetches it from the source and caches it.
  19. *
  20. * @param url The URL of the HTML document.
  21. * @return The HTML content as a string.
  22. * @throws IOException If an error occurs during fetching or caching.
  23. */
  24. public String getHtml(String url) throws IOException {
  25. if (cache.containsKey(url)) {
  26. System.out.println("Retrieving from cache: " + url);
  27. return cache.get(url);
  28. }
  30. System.out.println("Fetching from source: " + url);
  31. String html = fetchHtml(url); // Fetch HTML content from the source
  32. cache.put(url, html); // Cache the fetched HTML content
  34. // Evict the least recently used entry if the cache is full
  35. if (cache.size() > cacheSizeLimit) {
  36. evictLeastRecentlyUsed();
  37. }
  39. return html;
  40. }
  43. private String fetchHtml(String url) throws IOException {
  44. // Simulate fetching HTML from a source (e.g., a web server)
  45. // Replace this with your actual HTTP request implementation
  46. return "<html><body><h1>HTML Content for " + url + "</h1></body></html>";
  47. }
  50. private void evictLeastRecentlyUsed() {
  51. if (cache.isEmpty()) {
  52. return; // Nothing to evict
  53. }
  55. String oldestKey = null;
  56. for (String key : cache.keySet()) {
  57. if (oldestKey == null || key.compareTo(oldestKey) < 0) {
  58. oldestKey = key;
  59. }
  60. }
  62. cache.remove(oldestKey); // Remove the least recently used entry
  63. }
  64. }

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