利用 Base64 缩短 UUID 至22位

编程技术  /  houtizong 发布于 3年前   54

UUID还是比较常用的，尤其在web应用里。

有时在URL中传播，感觉比较长，于是想对其进行缩短，查询了一些资料，发现目前最短是到 22 位（使用URL传播非转义字符，结合Base64）

 

废话少说，代码奉上：

public class UuidBase64ShortMap implements StringShortMap{    /**     *     *把UUID 转为 22位长字符串     */    public String shorter(String s) {        char[] res = Base64.encode(asBytes(s));        return new String(res,0,res.length-2);    }   /**     *     *把22位长字符串转为 UUID     */    public String recover(String s) {        int len = s.length();        char[] chars = new char[len+2];        chars[len]=chars[len+1]='_';        for(int i=0;i<len;i++){            chars[i]=s.charAt(i);        }        return toUUID(Base64.decode(chars)).toString();    }    public static byte[] asBytes(String id) {        UUID uuid=UUID.fromString(id);        long msb = uuid.getMostSignificantBits();        long lsb = uuid.getLeastSignificantBits();        byte[] buffer = new byte[16];        for (int i = 0; i < 8; i++) {                buffer[i] = (byte) (msb >>> 8 * (7 - i));        }        for (int i = 8; i < 16; i++) {                buffer[i] = (byte) (lsb >>> 8 * (7 - i));        }        return buffer;    }    public static UUID toUUID(byte[] byteArray) {        long msb = 0;        long lsb = 0;        for (int i = 0; i < 8; i++)                msb = (msb << 8) | (byteArray[i] & 0xff);        for (int i = 8; i < 16; i++)                lsb = (lsb << 8) | (byteArray[i] & 0xff);        UUID result = new UUID(msb, lsb);        return result;    }        public static void main(String[] args) {                StringShortMap shortm = new UuidBase64ShortMap();//        String uuid = "3b01174f-3139-4a5b-a949-bb7e80b55f91";//        System.out.println(Base64.encode(uuid));//        String shorter= shortm.shorter(uuid);//        System.out.println(shorter);//        System.out.println(shortm.recover(shorter) +"\t" + uuid);        //        for(int i=0;i<100000;i++){//            String Uuid = UUID.randomUUID().toString();//            System.out.println(Uuid +"\t" + shortm.shorter(Uuid));//        }                String[] uuids={"f6e0e040-be3d-4573-964c-88724a8fa7d3","c19b9de1-f33a-494b-afbe-f06817218d63","f08f0b2c-66fb-41a3-99c3-ac206089c3ad"};        for(String s :uuids){            System.out.println(shortm.shorter(s));        }    }}

运行结果

9uDgQL49RXOWTIhySo*n0wwZud4fM6SUuvvvBoFyGNYw8I8LLGb7QaOZw6wgYInDrQ

 

有更好的方案，欢迎讨论！！