java Web应用程序中的唯一序列号 [英] Unique serial number in a java web application

问题描述

我一直想知道生成独特ID的正确做法是什么？事情是在我的网络应用程序中我将有一个插件系统，当用户注册一个插件我想为它生成一个唯一的序列ID。我一直在考虑将所有数字存储在数据库或服务器上的文件中，生成一个随机数并检查它是否已存在于数据库/文件中，但这似乎不太好。还有其他方法吗？使用UUID是首选方式吗？

I've been wondering what's the correct practice for generating unique ids? The thing is in my web app I'll have a plugin system, when a user registers a plugin I want to generate a unique serial ID for it. I've been thinking about storing all numbers in a DB or a file on the server, generating a random number and checking whether it already exists in the DB/file, but that doesn't seem that good. Are there other ways to do it? Would using the UUID be the preferred way to go?

推荐答案

如果id是面向用户的，它们看起来是，然后你想让它们难以猜测。使用内置的 UUID 课程，该课程为您生成随机ID可以为你很好地格式化它们。提取：

If the ids are user-facing, which it seems they are, then you want them to be difficult to guess. Use the built-in UUID class, which generates random ids for you and can format them nicely for you. Extract:

UUID idOne = UUID.randomUUID();
UUID idTwo = UUID.randomUUID();
log("UUID One: " + idOne);
log("UUID Two: " + idTwo);

示例输出：

UUID One: 067e6162-3b6f-4ae2-a171-2470b63dff00 
UUID Two: 54947df8-0e9e-4471-a2f9-9af509fb5889

提供的链接中还有其他解决方案。我认为它很好地比较了这些方法，所以选择最适合你需要的方法。

There are other solutions in the link provided. I think it compares the methods quite well, so choose the one which best suits your needs.

另一种有趣的方法是 MongoDB 使用，但这可能是你的需求过度：

Another interesting method is the one MongoDB uses, but this is possibly overkill for your needs:

BSON ObjectID是一个12字节的值
，包含一个4字节的时间戳
（自纪元以来的秒数），一个3字节的
机器ID，一个2 -byte进程id和
3字节计数器。请注意，
时间戳和计数器字段必须是
存储大端，不像其他
BSON

A BSON ObjectID is a 12-byte value consisting of a 4-byte timestamp (seconds since epoch), a 3-byte machine id, a 2-byte process id, and a 3-byte counter. Note that the timestamp and counter fields must be stored big endian unlike the rest of BSON

如果他们不是面向用户，那么你可以将它留给数据库来做一个自动递增的id：1,2,3等等。

If they weren't user facing, then you could just leave it to the database to do an auto-incrementing id: 1, 2, 3, etc.

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