uuid

I am using Javas UUID and need to convert a UUID to a byte Array. Strangely the UUID Class does not provide a "toBytes()" method. I already found out about the two methods: UUID.getMostSignificantBits() and UUID.getLeasSignificantBits() But how to get this into a byte array? the result should be a byte[] with those tow values. I somehow need to do Bitshifting but, how? update: I found: ByteBuffer byteBuffer = MappedByteBuffer.allocate(2); byteBuffer.putLong(uuid.getMostSignificantBits()); byteBuffer.putLong(uuid.getLeastSignificantBits()); Is this approach corret? Are there any other methods

在运营中，有时会碰到线下下单，线下注册，需要在数据库对其数据批量生成导入的场景。 此时如果你的数据表主键并不是Int整型自动递增而是32位的UUID这种情况该怎么办呢？ MySQL 其实实现了UUID，并为我们提供UUID()函数。 用法如下： mysql> SELECT UUID(); mysql> c2cb8f66-351f-11e7-b3ed-00163e0429b6 mysql> SELECT REPLACE( UUID(), '-', ''); #将'-'符号替换掉 mysql> 45c87fa0352211e78d40d4977a9ea871 在 MySQL 的 UUID() 函数中，前三组数字从时间戳中生成，第四组数字暂时保持时间戳的唯一性， 第五组数字是一个 IEEE 802 节点标点值，保证空间唯一。使用 UUID() 函数，可以生成时间、空间上都独一无二的值。 据说只要是使用了 UUID，都不可能看到两个重复的 UUID 值。 来源： https://www.cnblogs.com/zhuyeshen/p/11890148.html

I need to implement UUID as primary key but I'm not sure how to do it in Django. My code class LinkRenewAd(models.Model): # This model will generate the uuid for the ad renew link def make_uuid(self): return str(uuid.uuid1().int>>64) uuid = models.CharField(max_length=36, primary_key=True, default=make_uuid, editable=False) main = models.ForeignKey(Main) expiration_date = models.DateTimeField() date_inserted = models.DateTimeField(auto_now_add=True) date_last_update = models.DateTimeField(auto_now=True) When I try to generate this new model on South I got the error: TypeError: make_uuid()

计算机信息查看-. import platform import platform def TestPlatform(): print("---------SYSTEM INFO--------") #获取Python版本 3.7.1 print(platform.python_version()) #获取Python版本 v3.7.1 print(platform.python_branch()) #获取操作系统可执行程序的结构 (’32bit’, ‘WindowsPE’) print(platform.architecture()) # 计算机的名称 DESKTOP-90JE76G print(platform.node()) # 获取操作系统名称及版本号，Windows-7-6.1.7601-SP1 print(platform.platform()) # 计算机处理器信息， Intel64 Family 6 Model 158 Stepping 10, GenuineIntel print(platform.processor()) # 获取操作系统中Python的构建日期 ('v3.7.1:260ec2c36a', 'Oct 20 2018 14:57:15') print(platform.python_build()) # 获取系统中python解释器的信息 MSC

I want to attach a UUID to a field in my protobuf User message example. message User { // field containing id as UUID type required string email; optional string name; } I know that protobuf messages do not yet support the UUID type. I've read that the best approach is to have a UUID message type. So I'm guessing my User message would import my UUID message proto definition and use it as a field type like so: import "myproject/UUID.proto"; message User { required UUID id; required string email; optional string name; } My question is, how will the UUID message look like, and how will I encode

I couldn't find a self-contained UUID5 implementation for Java, so I tried rolling this solution below. It passes some of my unit tests but fails others. Any obvious bugs in this? public static UUID UUID5(UUID namespace, String name) { MessageDigest md; try { md = MessageDigest.getInstance("SHA-1"); } catch (NoSuchAlgorithmException nsae) { throw new InternalError("SHA-1 not supported"); } byte[] namespaceBytes = ByteBuffer.allocate(16).putLong(namespace.getMostSignificantBits()).putLong(namespace.getLeastSignificantBits()).array(); byte[] nameBytes; try { nameBytes = name.getBytes("UTF-8"); }

uuid1：IEEE 802 MAC地址 import uuid ''' UUID1值使用主机的MAC地址计算。uuid模块使用getnode函数来获取当前系统的MAC值 ''' print(uuid.getnode()) # 70561824630575 # 如果一个系统有多个网卡，那么相应地便会有多个MAC地址，并且可能返回其中任意一个值 # 要为一个主机(由其MAC地址标识)生成一个UUID，需要使用uuid1函数。节点标识符参数是可选的。如果没有设置这个域，那么便会使用getnode返回的值 u = uuid.uuid1() print(u) print(type(u)) print(f"bytes:{u.bytes}") print(f"hex:{u.hex}") print(f"int:{u.int}") r''' 3e5fc450-51f7-11e9-ad5d-402cf47de72f <class 'uuid.UUID'> bytes:b'>_\xc4PQ\xf7\x11\xe9\xad]@,\xf4}\xe7/' hex:3e5fc45051f711e9ad5d402cf47de72f int:82909385656127884677084089467799463727 ''' UUID 3和5：基于名字的值 import uuid '''