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！！