UUID (Java)

1. Introduction

TBD

20. Short UUID

Generating UUIDs using and then translating them to base57 using lowercase and uppercase letters and digits, and removing similar-looking characters such as l, 1, I, O and 0.

Reference: defensefinalwork

Encoded UUIDs have 22 characters, eg:

UUID                                    ShortUuid

--------------------------------------------------------------

b898a7ce-96c6-4ff9-a84b-69b3492ec1ff    fkzEZpZU9VdvuQh6Eeo6ra

ec6dc62c-3f93-477f-8cd0-f3535333096b    UoGiH549ghxuaJBhxCQk5k

20.1. Usage

//New shortUuid

String shortUuid = (new ShortUuid.Builder()).build().toString();

//UUID to shortUuid

UUID uuid = UUID.randomUUID();

String shortUuid = (new ShortUuid.Builder()).build(uuid).toString();

//shortUuid to UUID

UUID uuid = UUID.fromString((new ShortUuid.Builder()).decode(shortUuid)));

20.2. Code

The following code is based in the one by hsingh at https://github.com/hsingh/java-shortuuid from 2015-nov-8.

The issue "Padding length is wrong" has been fixed replacing Math.log(25d) by Math.log(256d).

ShortUuid.java

package com.hsingh.shortuuid;

import java.math.BigInteger;

import java.util.Arrays;

import java.util.UUID;

/**

 * A short, unambiguous and URL-safe UUID

 *

 * @author Harpreet Singh

 */

public final class ShortUuid {

    private final String uuid;

    private ShortUuid(String uuid) {

        this.uuid = uuid;

    }

    @Override

    public String toString() {

        return uuid;

    }

    @Override

    public int hashCode() {

        return uuid.hashCode();

    }

    @Override

    public boolean equals(Object o) {

        if (o == this)

            return true;

        if (!(o instanceof ShortUuid))

            return false;

        return ((ShortUuid) o).toString().equals(uuid);

    }

    public static class Builder {

        private char[] alphabet = "23456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"

            .toCharArray();

        private int alphabetSize = alphabet.length;

        public Builder() {}

        public Builder alphabet(String alphabet) {

            this.alphabet = alphabet.toCharArray();

            Arrays.sort(this.alphabet);

            alphabetSize = this.alphabet.length;

            return this;

        }

        public ShortUuid build() {

            return build(UUID.randomUUID());

        }

        public ShortUuid build(UUID uuid) {

            String uuidStr = uuid.toString().replaceAll("-", "");

            Double factor = Math.log(256d) / Math.log(alphabetSize);

            Double length = Math.ceil(factor * 16);

            BigInteger number = new BigInteger(uuidStr, 16);

            String encoded = encode(number, alphabet, length.intValue());

            return new ShortUuid(encoded);

        }

        public String decode(String shortUuid) {

            return decode(shortUuid.toCharArray(), alphabet);

        }

        private String encode(final BigInteger bigInt, final char[] alphabet, final int padToLen) {

            BigInteger value = new BigInteger(bigInt.toString());

            BigInteger alphaSize = BigInteger.valueOf(alphabetSize);

            StringBuilder shortUuid = new StringBuilder();

            while (value.compareTo(BigInteger.ZERO) > 0) {

                BigInteger[] fracAndRemainder = value.divideAndRemainder(alphaSize);

                shortUuid.append(alphabet[fracAndRemainder[1].intValue()]);

                value = fracAndRemainder[0];

            }

            if (padToLen > 0) {

                int padding = Math.max(padToLen - shortUuid.length(), 0);

                for (int i = 0; i < padding; i++)

                    shortUuid.append(alphabet[0]);

            }

            return shortUuid.toString();

        }

        private String decode(final char[] encoded, final char[] alphabet) {

            BigInteger sum = BigInteger.ZERO;

            BigInteger alphaSize = BigInteger.valueOf(alphabetSize);

            int charLen = encoded.length;

            for (int i = 0; i < charLen; i++) {

                sum = sum.add(alphaSize.pow(i).multiply(BigInteger.valueOf(

                    Arrays.binarySearch(alphabet, encoded[i]))));

            }

            String str = sum.toString(16);

            // Pad the most significant bit (MSG) with 0 (zero) if the string is too short.

            if (str.length() < 32) {

                str = String.format("%32s", str).replace(' ', '0');

            }

            StringBuilder sb = new StringBuilder()

                .append(str.substring(0, 8))

                .append("-")

                .append(str.substring(8, 12))

                .append("-")

                .append(str.substring(12, 16))

                .append("-")

                .append(str.substring(16, 20))

                .append("-")

                .append(str.substring(20, 32));

            return sb.toString();

        }

    }

}

ShortUuidTest.java

package com.hsingh.shortuuid;

import static org.junit.Assert.*;

import java.util.UUID;

import org.junit.Test;

public class ShortUuidTest {

    public String[][] getTests() {

        return new String[][] {

            {"c3eeb3e6-e577-4de2-b5bb-08371196b453", "nSKHvGZM4M5A4KyN4zp4sc"},

            {"7c37b0a5-9d63-4d91-a79e-85a480fd2348", "gos3umowEP9bS8QAGSuk7Q"},

            {"52600a3d-a12a-4041-aa9c-afd5e5923a70", "ZHhWmgrdXxgMqzgYRXGRfG"},

            {"7b80853c-a9f3-4acd-b735-17d29b3b9122", "gGpmQT6oVMVeQvnLkgJWyP"},

            {"2f56ebd5-373f-478f-afab-1142b74b75bc", "Hi7d4MYcbjKxzeg8YiN7SA"},

            {"72573478-ade8-4a6c-a583-d098e9c24de3", "yoANdrf88xUXvwbS5GRbMN"},

            {"f4c03714-aa7e-42e3-91f8-9a7a3bc05f75", "VTtAQPXV7MRyAghQPA6AZm"},

            {"f9ee01c3-2015-4716-930e-4d5449810833", "7fm8A5kT3j9j5M2HcjofUn"},

            {"a5fb9251-9373-486b-b9bd-ecf1c7cc6d9c", "DQqWKCLAjsm6fTTFCwuKYX"},

            {"9cbfe3da-dc50-4d07-9d3a-3d161e5a82b1", "dhRv9nyctV3M6uUJtcZgtV"},

            {"cda34e96-188b-41b2-acac-05cd288c32e1", "Cekw67uyMpBGZLRP2HFVbe"},

            {"0ce70d9e-830e-404b-8b56-25cc611eed6a", "qXPoF8kNjxoqWZVCnoXrJ4"},

            {"36a06807-8c07-4e65-8b99-855b3628c155", "LXuzZwRWpEYos2yAiDmziB"},

            {"4672c1dc-125a-4469-a81e-c69dc3b8f792", "p6tjrWt5UH9RpAUqPfjTYE"},

            {"e63d7da2-7f8d-4954-9c2d-d46b324d10f2", "P3bYrwnrsvRXdsRCTByyxi"},

            {"926251a7-41a3-4029-bf44-bf860e881423", "r3FdNDkxMf4rdz8V7dcZ4U"},

            {"464a919f-54e9-435e-a029-a3b942b07134", "THvwuXRQt9soLzL3L2zrWE"},

            {"7c24ef71-f4eb-4000-afb6-710c7f9e0942", "9tXMVg3xaJxwuK7v4XZ27Q"},

            {"d3973d0f-22e4-44b5-a03f-34a57458a8ff", "rqcFhGVXy7quTXiERRPref"},

            {"74102102-3d04-48fc-b2b5-6ef50109e27f", "v8tx4KDUXyfSFcSmFZ45fN"},

            {"67cdb44b-f0fb-47c1-9060-025216c14067", "nD4n6pXuc9BanbiQM6HjUL"},

            {"503c91b0-6a52-4b26-be71-b96c1d4d908b", "fq2q5eoUmgGuuKTtCa3jHG"},

            {"174ea6fa-9321-4e80-b732-006b11998663", "zw3YBp3erLmWGWFvNW8PA6"},

            {"fa60d3a9-df24-468c-8006-e2a4f37ddf17", "zohky26otniDxSonDD6EZn"},

            {"eff670a0-75f5-4458-afd4-9aa442dcc507", "feViSxBJPp7ZUgCA2hCbhk"},

            {"2c301095-3f99-4fc8-88e3-a2be83fd39fc", "YAJdktpVp9ioZXyerGS9s9"},

            {"ee2d3de2-4ad7-4f32-9071-f8aa4b46dc0b", "XrKarC8cp4dWSRnWQjoUPk"},

            {"12942a1b-cf39-44d6-bfbb-0ae17affd408", "tYx4TiGiu78HcFfkmgkRK5"},

            {"f9b2ea09-32c6-426b-bb3b-a269182e99f3", "b7rFanuSDdkVW4Af7vNLSn"},

            {"02f3da16-b995-445a-877b-2319f0c06b41", "5aQC5t9BRRcicH9GbfmwX2"},

            {"b8538991-0957-4bab-93f3-7f78ca9c1550", "vDJmAtHGFpqmrP6MNTjMoa"},

            {"3bf87639-ba74-463e-9455-bf7bcb8fd898", "4pUYNRFHTG3YVgThPZvCgC"},

            {"c9c7cafa-a131-4193-a21d-b65d0052f77b", "ziGxvYy3dYbecxB2VPNNud"},

            {"f921ebe3-2d1b-42fc-951b-7b275d5a1e5f", "pwt3bwxM4WTMGRqNTuxaLn"},

            {"c3d5e2c5-1bc8-4a86-96fb-bf0877c9fc03", "UNqNwmt3Eb9TDXRJXon5rc"},

            {"582dd24f-beda-42cf-b751-7c7e9827b7d1", "cjhuJfBhZQiSZ7GkYPGHhH"},

            {"6dfacd19-5cfd-4b95-92be-7e9fb0fe343e", "C6wrxXg46LWXAnhNTyVNaM"},

            {"ea3f3050-d7ce-4ad7-ae24-9b7b164dcec1", "r29MuyWbYNZ75FhWmh5dgj"},

            {"07dcc180-1323-4985-8359-296261dd53c8", "Qw7DZuPhurJbWAAGwhwjQ3"},

            {"89ffb519-4cea-4cd2-b051-0da7b451ca1a", "q7C7JQRar8QxqhkePNRXZS"},

            {"81fa1f63-389e-44ae-906d-4c1f4a715a61", "mQVvJQHRPinBYydtDaHB9R"},

            {"77eee831-5e48-400b-b1e1-31bc8d28876e", "hnGWZSNK7xyhivxQoYJKMP"},

            {"63815548-e46f-441a-8bdf-3153db75e56b", "Qnmrn7WRTv2kmDC5oNZ9iK"},

            {"60cba957-dc15-404a-994a-cab6b11b1315", "po3Y5UByzV7T8ny9fvCfEK"},

            {"a23360e0-1caf-4275-b957-0bcd7aa109d8", "mRV85qM4gaVEVidUCrfxrW"},

            {"48610926-01fb-4ef8-ae6b-ba9b45569525", "4YcLEHE6evYdnN9R6Er3tE"},

            {"c1d07707-c751-4e18-bf53-924a02e7a312", "tfdCPzDgjH7kDZmoUbRaVc"},

            {"d22b3035-2213-49a8-8399-a547303f29a3", "9K49a86KhGxzjfdt8YLSQf"},

            {"ba40a392-f1f6-4486-8c27-00b78db13ddc", "iHHZerT4hpfGqMbjuXCt9b"},

            {"241d6b4e-81a7-439a-896d-b645ec223eb5", "fuTJdCqF7jvgn6p8ZRoGS8"},

            {"e2f1fc6f-c8c8-4e6c-91ff-aca0ca558535", "qHhWwrK3ZPHZ3w5LDjHaPi"},

            {"b6f1e412-da4f-43bf-8a9f-ae4658f5b9ce", "7EohUgpsHtHugJudodBMZa"},

            {"db850c2c-a4e2-45c5-9b67-fda3be319df2", "uAQEWZNR9MQrqTVCU3qG5h"},

            {"63ac6e18-e0c9-477d-b08f-039b9538e577", "Qh3dcsgZBQCseB34xNsqjK"},

            {"eda9eacb-d698-41af-8790-4f26ecbd3a39", "29XrEqVWgteJF2Kr6xGHJk"},

            {"76d61350-f831-40fe-ae88-c2d63885c954", "u6xS5LyehZPedbnBRjACAP"},

            {"9dc996f5-2dfb-4e60-96a2-f11f59eb71de", "B8tRdDRCz6spwRDVPoXD6W"},

            {"9e0ef764-f98d-4c66-abd8-5d5e7392bacb", "TsnXJsfNMZGvuu9WJHCx8W"},

            {"08c79281-f45e-4463-b26d-1dc84ece1a05", "VgbLFBmKXHXs5VZdxuB4a3"},

            {"6611ce43-fe22-47ef-879e-de3fbbd4d9f6", "HHsWgxyECxDUUdNKEvu9BL"},

            {"748374a4-43c4-42a4-92be-f70daffe5d58", "h6793J2TNezTRPo8iFUdjN"},

            {"eb571f9d-dbe4-4d37-840f-0db7c9a35e3a", "snrX2R8WkCAALQ5Ux6Cisj"},

            {"dbc3f7d2-5f4b-4fb9-b473-2ca74cf7e2ef", "WRGi6eUnSKwVAaCwcXuk7h"},

            {"4e4d65f0-22b1-48ba-acc4-b378e7a826e3", "ybEmP4TsGe53BYtqDAu7wF"},

            {"c5232425-c634-4653-a367-0eb07235ccfc", "U6XjtF8PADo2bW7Gd6KH6d"},

            {"8a95bedb-0592-4329-87be-8affdf5f2e97", "ck493bWVpcBsppo94mDUfS"},

            {"52fa1417-02e9-4656-96ec-5cf44fdcd3c2", "RyF2UdmNpgzbxjNVbo6XmG"},

            {"d728fb9b-240b-4ca1-b864-50b807364acb", "y3kctB9VyUVeDABHVQg4Jg"},

            {"9da4fb93-9260-46a7-b6df-f04218560fe0", "jxBVLETqKeFjofyJe8sk4W"},

            {"fa9c1ef1-1f4d-4b74-9590-878c79f1f353", "xKpbsbfBxJA5r5uC7wxZbn"},

            {"64d1355f-d052-4bd9-83f4-39b93fb1c01f", "fCd2nkGhNF9UBcxpDsySwK"},

            {"7227d320-fd77-4430-8e9c-ac3f93e07c51", "crnPpyJpmterz6sLUwRiKN"},

            {"22eac9a7-b0b7-4c8b-9e88-4a2c4a48eef4", "PKMNKhycsviQJbcG3uQ8E8"},

            {"68252941-638b-4e0d-807a-3e8cd04f2493", "iRPfmXvLunFTvtoanekCYL"},

            {"3c9886b3-cabc-4854-8fe3-d394c0901830", "ELPAWnjUbWpbS3xhJSNYnC"},

            {"37eea0c0-ec18-42e8-a152-c98fee7346fb", "QgZm5asemZJYKqpCJrTFxB"},

            {"a61daaac-ea00-4bba-89d9-22b97763a43a", "aCfFqp3vmiADaHuL6LufZX"},

            {"1fc9211b-c1b8-464e-ae01-1c59d1972f47", "ENBaEjcoJktWRqfBkVDNf7"},

            {"21e24536-3b3e-4166-85c4-c29ea151fbbe", "LNZqphXG6tigmWJeBt7e38"},

            {"94fac6e4-315c-4399-89c0-0c5bdd5bf206", "w6qsE9trfLSjwUMjzxzsWU"},

            {"e9ae9ba7-4fb1-4a6d-bbca-5315ed438371", "vACGXSMs5eYcfXgAAjbtaj"},

            {"39439367-6f10-4de8-883f-7ace28c3bc33", "KSbYQEttmBpDjSkUxEMkCC"},

            {"ac6250d9-6e12-4686-98b2-3e5e8ab11ecb", "ZZVXrsGQdVqLz4JGNdKFgY"},

            {"f1975e43-a054-4243-85b1-14ed27be8330", "Bb45oofgN75sPKJYWWe7zk"},

            {"9206e127-8559-4cc4-877e-5cf342aecd25", "7LppjN8wAobe3FXybT9wyT"},

            {"4aeff9a2-4ad2-4c85-abd1-95e798b2132a", "JPu3vSYW3LEGp7RTMSkyLF"},

            {"c7c541b0-d024-432e-8b84-dcc011bfb596", "ag4yKsYNczpg2gKA3TWyYd"},

            {"852fcc13-5632-4188-92a8-12909c77f83f", "tJusodB6eZxNyVrGXGgihR"},

            {"97d87c66-f983-48b7-84c4-1d521e790ecf", "jYFL8gwyq9inicFz4dmw2V"},

            {"4f800ff2-7c1a-4305-b7d5-ce4c5b08e928", "wGSD5xRu6Kc9z8PrFsNGAG"},

            {"185c8229-dbd0-4fc1-a485-04a0532a71d0", "huiUUTVakc3eBxVmQgU5M6"},

            {"0170eb09-dd9d-4682-a58f-b49eb481a40d", "YE6XcuFs8SBnRhgVcS4dG2"},

            {"d11c27c7-e302-4007-8a82-a83f57da217a", "uRQsP9P54sbnWjw66uKhDf"},

            {"4ef326fe-7886-4054-b427-4cd9f48200bf", "ibgFYZiZccqvy2PrsMCg4G"},

            {"9e5366f3-6bb8-42db-b999-1dc3612be8e4", "nWdjqVaVdyt94U794eifBW"},

            {"75a8dcb5-9e11-4fbb-895b-60bb6959b6e7", "9tvqGWgZgfiq2mPAvazFwN"},

            {"2b3bd265-a475-401d-88a6-3aa8580483ba", "zdGUGgimEzGkL65LnmuTh9"},

            {"7273ea84-04a1-4d32-92ff-b0afad3eedb6", "6FBBvgSqZeKBpyxxBfFjNN"},

            {"d2af90cd-1b97-4bec-810b-562406b31470", "aTfqZJoFH5kXHiYGxoFgVf"},

            {"8ec76efb-b891-4ee4-868d-997597e390e1", "mdoaq3unkSKHuuDKc6gzQT"},

            {"431933fb-14dd-411c-8fc6-5ca57fa7979d", "ajLWxEodc6CmQLHADuKVwD"},

            {"4788fd99-a1f3-468a-bc67-ada5f80016f4", "QvqUofYurTwpHNWUG52VjE"},

            {"502f56e0-f351-4f42-b395-4dde8b8c19b6", "B8tAKsW9Zw6ZRHySjmADHG"},

            {"b3150123-4e7c-4080-a029-c7437c6513df", "JYqm5dazak2ye8hfs7DBsZ"},

            {"61714a37-a894-4ec5-a569-7e925b46e368", "no6QHS2MfYKUZ6ys4xCEMK"},

            {"8a2f74ed-8146-4f86-a50a-aa28a21c3829", "t3HZ5drXDpPRgjuEnBFRbS"},

            {"5ea5a1a8-bd7e-46fd-ae88-e2d779bc9453", "uQod4vaUSE3ciZdwbbCsqJ"},

            {"35165d02-262d-4e30-8344-c70ee9cc63ee", "DjB4ac8mxbB25FCQswyPTB"},

            {"0026636a-e9b3-4a88-9c66-bf49d8cad81f", "BcRZF3N5Bv7FcJTEsxgX32"},

            {"84973303-f7ff-47a0-8b47-c54767700622", "kzcnTJSM4nPRXJT89Q7gbR"},

            {"92faac68-0387-49ae-a219-45e7c13fd6a3", "Rw8KtoWPAvbt2EqPtAebAU"},

            {"e9f17c46-0d3d-45e8-bc36-6c793b59c91c", "QXh7kFCLxJkJjayBAXcYdj"},

            {"d39295c8-f4d8-407f-bcdf-d07911f4d997", "tWkeanmnjjupCMcjnUsfef"},

            {"a2952f3b-fba2-4926-b19d-26d550093b93", "VEaZCnxWXK6VryEoLUXqvW"},

            {"40e86d7b-77dd-4f55-aec8-29262e028c38", "3Ad8xKbmR43ud53T7Y4HZD"},

            {"c6876847-fda6-4ab5-a2c2-9d8fe9c543bc", "Bj5frkc73iykq7XVT6nPLd"},

            {"cf5c7de8-82d2-475f-a078-825b76d0a287", "PzWDnpB8hSu8cZN38AUxte"},

            {"c4560036-bd08-42d6-ba59-1a49a51643df", "zYWYB5k4sQ55k4KL7V6Awc"},

            {"ded85fd3-afe7-45a1-a4d8-90c0a5bc8901", "MDkC9BQWzG7RPvHpCGCzeh"},

            {"f8221ca8-49e2-44e5-a104-7cec6fb28d48", "Q682Tt3m3ohTTdoGZgLTAn"},

            {"c1544cac-c6ee-40a7-98c8-900a7282ae22", "43nxCsa2kHWeAK32kG4fQc"},

            {"422a2339-0950-4a68-aec1-8c4056feef2a", "SBxqULeq9wXZskuxLoV2nD"},

            {"d9f26801-08d7-42e2-adee-e178944d9ba9", "z2QKKXd38qApcjuav6eKng"},

            {"69807fd5-8bcf-4d4c-a534-ff298d4a5a0a", "fe9aUtsDhyC9ssuU2Y5xmL"},

            {"65656f1e-ae8d-48a3-825d-4499144eefab", "bGSD7rg3Xm2Y4mjNDygK4L"},

            {"0a4399e6-7fad-452b-acc8-1d6b33415019", "NzVFQCNbRxxccPCpHRK7q3"},

            {"4860e725-08f5-4ba1-87e6-1db791f183d8", "8Ka6kDcVRxniasWrb8Z3tE"},

            {"709a8e5a-6320-4649-b4c2-8aceb28502ae", "ekLbSTDNHj9XSCjo6XNy3N"},

            {"3b6aa689-ab23-4ded-932d-090e029a7a99", "4PjpHyzbdreNeUxSc3iaaC"},

            {"00302322-9d08-4394-a1ac-b25bbab774d4", "zv3wa6Hm2fK2SaaRLkhu32"},

            {"12a12ca0-0d6e-4b84-bd6f-9715d467ae76", "iCLCA6LpyQKnw3TexB9wK5"},

            {"6556f0b7-b826-4ed3-b2ef-911a1d0665c8", "RfzKJAwgPxnMD24SEVxj3L"},

            {"269ca19c-5937-4512-83f8-ab9ab82cdaab", "nUkCVCrYTu7LBY8eDPCbs8"},

            {"58f3c051-a71a-4608-bf4e-543694f65f6b", "kKorfq5sQENdZGWDPuC8qH"},

            {"13f0a717-883d-4a69-b7da-eeb91f5d5ca5", "Dke3AiNbfvWUjq6W5bfEZ5"},

            {"7d2ec191-96ef-4b3d-834e-94cf60b1467f", "6mVb7WwQ8tcas48qYJoYHQ"},

            {"831805c0-7651-4a0d-804e-d12924bb9a0c", "pZ6gS9wWUXdHr64W7jrVLR"},

            {"56a03672-74bc-418c-9964-76548fd5b209", "9qiVxV4fEdYvhaW5PBSXRH"},

            {"8c634f54-f7bf-4f39-bf84-394f06970eda", "YpGmB2LeJ6ms8jntjgTkyS"},

            {"a5d35565-a3e0-407f-ab1c-1b8a605ba172", "9bFhyhbykoBC3mdQcu4jWX"},

            {"48443c48-0632-4b72-ba41-f4bdd0cd8ef5", "8ZmSNTgRwuf3qD5ZuLptrE"},

            {"1e86f5b0-b479-4dd2-9d3c-0c0b9a63db30", "WbphNvGKPP8bQE9y65jbS7"},

            {"7178fac6-27b6-473d-801a-63be24d75fb2", "bTdfo4UL4NWDXoMttdcnCN"},

            {"8e03626b-9c23-4032-9ee2-ae6ca661b7d1", "zvvZNCeKsWEQwYrP4dyEHT"},

            {"51f7acb3-2a82-4cc6-8601-523ed6d5909b", "EdQ8N465wYULNARFAfbHbG"},

            {"676fcb0c-730c-4875-9c0b-62b0bc2f4b9e", "J7DMkkwPsVJnt6frUnD2RL"},

            {"2ab244e0-4e34-494f-8c1a-d91051a4c3bf", "E4VoERm26o5Rkfsp6NK2c9"},

            {"4c8c949d-5bef-4d56-82f9-2041859b1dc6", "sEsXtdJXEnq9cLJuCrSLdF"},

            {"ca887b94-e90a-4143-b498-b0f517677e5a", "bLBXoAmYhoJvTHv2FVUz3e"},

            {"eb9ccaea-9569-4688-a40a-96fe3dd3d6eb", "89hHCpRTfBuhi7hxJDWUvj"},

            {"00000000-0000-0000-0000-000000000000", "2222222222222222222222"},

        };

    }

    @Test

    public void testEncoding() {

        ShortUuid.Builder builder = new ShortUuid.Builder();

        String[][] tests = getTests();

        for (String[] test : tests) {

            ShortUuid shortUuid = builder.build(UUID.fromString(test[0]));

            assertEquals(test[1], shortUuid.toString());

        }

    }

    @Test

    public void testDecoding() {

        ShortUuid.Builder builder = new ShortUuid.Builder();

        String[][] tests = getTests();

        for (String[] test : tests) {

            String decodedUuid = builder.decode(test[1]);

            assertEquals(test[0], decodedUuid);

        }

    }

}