在保留唯一性的同时缩短 java UUID
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Shortening java UUID while preserving the uniqueness
提问by Fipil
I'm trying to make the java UUID shorter while preserving the same uniqueness as the UUID has. I wrote the following code:
我试图使 java UUID 更短，同时保留与 UUID 相同的唯一性。我写了以下代码：
public static void main(String[] args) {
UUID uid=UUID.randomUUID();
String shortId=to62System(uid.getMostSignificantBits())+
to62System(uid.getLeastSignificantBits());
System.out.println(shortId);
}
static char[] DIGITS = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();
static int RADIX = DIGITS.length;
public static String to62System(long value) {
if (value == 0) {
return "0";
} else {
char[] buf = new char[11];
int charPos = 10;
long i = value;
while (i != 0) {
buf[charPos--] = DIGITS[Math.abs((int) (i % RADIX))];
i /= RADIX;
}
return new String(buf, charPos + 1, (10 - charPos));
}
}
Am I doing it right or did I overlooked something important?
我做得对还是我忽略了一些重要的事情？
采纳答案by stikkos
I use org.apache.commons.codec.binary.Base64 to convert a UUID into a url-safe unique string that is 22 characters in length and has the same uniqueness as UUID.
我使用 org.apache.commons.codec.binary.Base64 将 UUID 转换为长度为 22 个字符且与 UUID 具有相同唯一性的 url-safe 唯一字符串。
I posted my code on Storing UUID as base64 String
我在将 UUID 存储为 base64 字符串上发布了我的代码
回答by MariuszS
Take a look at FriendlyIdlibrary. This library allow to encode UUIDto Base62string (Url62) and back. Uniqueness is achieved and encoded string is shorter.
看看FriendlyId库。该库允许将UUID编码为Base62字符串（Url62）并返回。实现了唯一性并且编码的字符串更短。
回答by Luke Visinoni
I believe even once you get it down to 22 characters by changing to base whatever, you can safely truncate a few characters and still be reasonably certain you won't get any collisions, as you probably know the astronomically large numbers involved. LOL loved the first guy's response thinking u were just like grabbing some characters from a standard UUID and calling it a day haha
我相信，即使您通过更改为基础将其减少到 22 个字符，您也可以安全地截断几个字符，并且仍然可以合理地确定不会发生任何冲突，因为您可能知道所涉及的天文数字。LOL 喜欢第一个人的回应，认为你就像从标准 UUID 中抓取一些字符并称之为一天哈哈
