利用 Base64 缩短 UUID 至22位

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*n0w
wZud4fM6SUuvvvBoFyGNYw
8I8LLGb7QaOZw6wgYInDrQ

 

有更好的方案，欢迎讨论！！