kristofer hat die Gist bearbeitet . Zu Änderung gehen
1 file changed, 52 insertions
UrlShortener.java(Datei erstellt)
| @@ -0,0 +1,52 @@ | |||
| 1 | + | import java.security.MessageDigest; | |
| 2 | + | import java.security.NoSuchAlgorithmException; | |
| 3 | + | import java.util.HashMap; | |
| 4 | + | import java.util.Map; | |
| 5 | + | import java.util.Random; | |
| 6 | + | ||
| 7 | + | public class UrlShortener { | |
| 8 | + | private Map<String, String> urlMap = new HashMap<>(); | |
| 9 | + | private static final String BASE_URL = "http://short.url/"; | |
| 10 | + | ||
| 11 | + | public String shortenUrl(String originalUrl) { | |
| 12 | + | String shortUrl = generateShortUrl(originalUrl); | |
| 13 | + | urlMap.put(shortUrl, originalUrl); | |
| 14 | + | return BASE_URL + shortUrl; | |
| 15 | + | } | |
| 16 | + | ||
| 17 | + | public String expandUrl(String shortUrl) { | |
| 18 | + | String shortKey = shortUrl.substring(BASE_URL.length()); | |
| 19 | + | return urlMap.get(shortKey); | |
| 20 | + | } | |
| 21 | + | ||
| 22 | + | private String generateShortUrl(String originalUrl) { | |
| 23 | + | try { | |
| 24 | + | MessageDigest md = MessageDigest.getInstance("MD5"); | |
| 25 | + | byte[] digest = md.digest(originalUrl.getBytes()); | |
| 26 | + | ||
| 27 | + | StringBuilder shortUrl = new StringBuilder(); | |
| 28 | + | Random random = new Random(); | |
| 29 | + | ||
| 30 | + | for (int i = 0; i < 6; i++) { | |
| 31 | + | int index = random.nextInt(digest.length); | |
| 32 | + | shortUrl.append(String.format("%02x", digest[index])); | |
| 33 | + | } | |
| 34 | + | ||
| 35 | + | return shortUrl.toString(); | |
| 36 | + | } catch (NoSuchAlgorithmException e) { | |
| 37 | + | e.printStackTrace(); | |
| 38 | + | return null; | |
| 39 | + | } | |
| 40 | + | } | |
| 41 | + | ||
| 42 | + | public static void main(String[] args) { | |
| 43 | + | UrlShortener urlShortener = new UrlShortener(); | |
| 44 | + | ||
| 45 | + | String longUrl = "https://www.example.com/some/long/url"; | |
| 46 | + | String shortUrl = urlShortener.shortenUrl(longUrl); | |
| 47 | + | System.out.println("Short URL: " + shortUrl); | |
| 48 | + | ||
| 49 | + | String expandedUrl = urlShortener.expandUrl(shortUrl); | |
| 50 | + | System.out.println("Expanded URL: " + expandedUrl); | |
| 51 | + | } | |
| 52 | + | } | |
Neuer
Älter