For random shorturl adjective-name pair is used

src/main/java/tk/draganczuk/url/Routes.java

@@ -20,20 +20,25 @@ public class Routes {
 		var body = req.body();
 		var split = body.split(";");
 		String longUrl = split[0];
+		boolean unique = false;
 
 		String shortUrl;
 		try {
 			shortUrl = split[1];
+			shortUrl = shortUrl.toLowerCase();		
+			if (urlRepository.findForShortUrl(shortUrl).isEmpty()) {
+				unique = true;
+			}
 		} catch (ArrayIndexOutOfBoundsException e) {
-			shortUrl = Utils.randomString();
+			do {
+				shortUrl = Utils.randomName();
+				if (urlRepository.findForShortUrl(shortUrl).isEmpty()) {
+				unique = true;
+				}
+			} while (unique == false);
 		}
 
-		shortUrl = shortUrl.toLowerCase();
+		if (unique && Utils.validate(shortUrl)) {
-		
-		var shortUrlPresent = urlRepository
-				.findForShortUrl(shortUrl);
-
-		if (shortUrlPresent.isEmpty() && Utils.validate(shortUrl)) {
 			return urlRepository.addUrl(longUrl, shortUrl);
 		} else {
 			res.status(HttpStatus.BAD_REQUEST_400);

src/main/java/tk/draganczuk/url/Utils.java

@@ -8,20 +8,39 @@ public class Utils {
 
 	private static final String SHORT_URL_PATTERN = "[a-z0-9-_]+";
 	private static final Pattern PATTERN = Pattern.compile(SHORT_URL_PATTERN);
+	
+	// The following lists are modified versions of the strings in
+	// https://github.com/moby/moby/blob/master/pkg/namesgenerator/names-generator.go
+	
+	private static final String[] adjective = new String[] {"admiring", "adoring", "affectionate", "agitated", "amazing", "angry", "awesome", "beautiful", 
+		"blissful", "bold", "boring", "brave", "busy", "charming", "clever", "compassionate", "competent", "condescending", "confident", "cool", 
+		"cranky", "crazy", "dazzling", "determined", "distracted", "dreamy", "eager", "ecstatic", "elastic", "elated", "elegant", "eloquent", "epic", 
+		"exciting", "fervent", "festive", "flamboyant", "focused", "friendly", "frosty", "funny", "gallant", "gifted", "goofy", "gracious", 
+		"great", "happy", "hardcore", "heuristic", "hopeful", "hungry", "infallible", "inspiring", "intelligent", "interesting", "jolly", 
+		"jovial", "keen", "kind", "laughing", "loving", "lucid", "magical", "modest", "musing", "mystifying", "naughty", "nervous", "nice", 
+		"nifty", "nostalgic", "objective", "optimistic", "peaceful", "pedantic", "pensive", "practical", "priceless", "quirky", "quizzical", 
+		"recursing", "relaxed", "reverent", "romantic", "sad", "serene", "sharp", "silly", "sleepy", "stoic", "strange", "stupefied", "suspicious", 
+		"sweet", "tender", "thirsty", "trusting", "unruffled", "upbeat", "vibrant", "vigilant", "vigorous", "wizardly", "wonderful", "xenodochial", 
+		"youthful", "zealous", "zen"};
 
-	public static String randomString() {
+	private static final String[] name = new String[] {"agnesi", "albattani", "allen", "almeida", "antonelli", "archimedes", "ardinghelli", "aryabhata", "austin", 
-		int leftLimit = 48; // numeral '0'
+		"babbage", "banach", "banzai", "bardeen", "bartik", "bassi", "beaver", "bell", "benz", "bhabha", "bhaskara", "black", "blackburn", "blackwell", 
-		int rightLimit = 122; // letter 'z'
+		"bohr", "booth", "borg", "bose", "bouman", "boyd", "brahmagupta", "brattain", "brown", "buck", "burnell", "cannon", "carson", "cartwright", 
-		int targetStringLength = 10;
+		"carver", "cauchy", "cerf", "chandrasekhar", "chaplygin", "chatelet", "chatterjee", "chaum", "chebyshev", "clarke", "cohen", "colden", "cori", 
-
+		"cray", "curie", "curran", "darwin", "davinci", "dewdney", "dhawan", "diffie", "dijkstra", "dirac", "driscoll", "dubinsky", "easley", "edison", 
-		return random.ints(leftLimit, rightLimit + 1)
+		"einstein", "elbakyan", "elgamal", "elion", "ellis", "engelbart", "euclid", "euler", "faraday", "feistel", "fermat", "fermi", "feynman", "franklin", 
-				.filter(i -> (i <= 57 || i >= 97))
+		"gagarin", "galileo", "galois", "ganguly", "gates", "gauss", "germain", "goldberg", "goldstine", "goldwasser", "golick", "goodall", "gould", "greider", 
-				.limit(targetStringLength)
+		"grothendieck", "haibt", "hamilton", "hardy", "haslett", "hawking", "heisenberg", "hellman", "hermann", "herschel", "hertz", "heyrovsky", "hodgkin", 
-				.collect(StringBuilder::new,
+		"hofstadter", "hoover", "hopper", "hugle", "hypatia", "ishizaka", "jackson", "jang", "jemison", "jennings", "jepsen", "johnson", "joliot", "jones", 
-						StringBuilder::appendCodePoint,
+		"kalam", "kapitsa", "kare", "keldysh", "keller", "kepler", "khayyam", "khorana", "kilby", "kirch", "knuth", "kowalevski", "lalande", "lamarr", 
-						StringBuilder::append)
+		"lamport", "leakey", "leavitt", "lederberg", "lehmann", "lewin", "lichterman", "liskov", "lovelace", "lumiere", "mahavira", "margulis", "matsumoto", 
-				.toString();
+		"maxwell", "mayer", "mccarthy", "mcclintock", "mclaren", "mclean", "mcnulty", "meitner", "mendel", "mendeleev", "meninsky", "merkle", "mestorf", 
-	}
+		"mirzakhani", "montalcini", "moore", "morse", "moser", "murdock", "napier", "nash", "neumann", "newton", "nightingale", "nobel", "noether", "northcutt", 
+		"noyce", "panini", "pare", "pascal", "pasteur", "payne", "perlman", "pike", "poincare", "poitras", "proskuriakova", "ptolemy", "raman", "ramanujan", 
+		"rhodes", "ride", "riemann", "ritchie", "robinson", "roentgen", "rosalind", "rubin", "saha", "sammet", "sanderson", "satoshi", "shamir", "shannon", 
+		"shaw", "shirley", "shockley", "shtern", "sinoussi", "snyder", "solomon", "spence", "stonebraker", "sutherland", "swanson", "swartz", "swirles", 
+		"taussig", "tesla", "tharp", "thompson", "torvalds", "tu", "turing", "varahamihira", "vaughan", "vaughn", "villani", "visvesvaraya", "volhard", 
+		"wescoff", "weierstrass", "wilbur", "wiles", "williams", "williamson", "wilson", "wing", "wozniak", "wright", "wu", "yalow", "yonath", "zhukovsky"};
 
 	public static boolean validate(String shortUrl) {
 		return PATTERN.matcher(shortUrl)
@@ -37,4 +56,8 @@ public class Utils {
 
 		return true;
 	}
+
+	public static String randomName() {
+		return adjective[random.nextInt(adjective.length)]+"-"+name[random.nextInt(name.length)];
+	}
 }

src/main/resources/public/index.html

@@ -85,7 +85,7 @@
             <br>
             <thead>
                 <tr>
-                    <td>Short URL</td>
+                    <td>Short URL (click to copy)</td>
                     <td>Long URL</td>
                     <td>Hits</td>
                     <td name="deleteBtn">&times;</td>