获得Java UUID.randomUUID冲突的机会有多大？ [英] How big is the chance to get a Java UUID.randomUUID collision?

问题描述

我需要在Java中创建一些唯一文件，我计划使用UUID.randomUUID来生成它们的名称。有没有机会为此发生碰撞？我应该做一些像bellow os我不应该担心这个吗？

I need to create some uniques files in Java and i plan to use UUID.randomUUID to generate their names. Is there any chance to get a collision for this? Should i do something like bellow os I shouldn't worry about this?

Integer attemptsToGenerateUUID = 1;

while (true) {
    UUID fileUUID = UUID.randomUUID();

    if (fileDoesNotExistwith this UUID name) {
        save file;
        break;
    }

    attemptsToGenerateUUID += 1;

    if (attemptsToGenerateUUID > 64) {
        return false;
    }
}

推荐答案

根据维基百科，关于随机UUID中重复的可能性：

According to wikipedia, regarding the probability of duplicates in random UUIDs:

只有在接下来的100年中每秒产生10亿UUID后，创建一个副本的概率大约为50％。或者，换句话说，如果地球上的每个人拥有6亿UUID，则一次重复的概率约为50％。

Only after generating 1 billion UUIDs every second for the next 100 years, the probability of creating just one duplicate would be about 50%. Or, to put it another way, the probability of one duplicate would be about 50% if every person on earth owned 600 million UUIDs.

我想同样的推理也适用于Java的UUID实现。所以不，你不应该担心这一点。

I guess the same reasoning applies to Java's implementation of UUID. So no, you should not worry about this.

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