Revision of UrlShortener.java

kristofer 已修改 1718984693. 還原成這個修訂版本

1 file changed, 52 insertions

UrlShortener.java(檔案已創建)

		@@ -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	+	}