UUID, GUID, CLSID

First, UUIDThe UUID meaning is the universal Unique identifier (universally unique Identifier), which is a standard for software construction and is also used by the Open Source Software Foundation (open Software Foundation, OSF) in Distributed computing environments (Di stributed Computing Environment, DCE) is part of the field. Chinese name Universal unique identification Code foreign language name universally unique Identifier abbreviation UUID category Identification code application distributed computing environmentDirectory1 Effect 2 compose 3 Application 4 codefunctionThe purpose of the edit UUID is for all elements in a distributed system to have unique identifying information, without the need to specify the identification information through the central control. In this way, each person can establish a UUID that does not conflict with others. In such cases, there is no need to consider the name duplication problem when the database is established. The most widely used UUID is Microsoft's globally Unique Identifiers (GUIDs), while other important applications are Linux EXT2/EXT3 file systems, Luks encrypted partitions, GNOME, KDE, Mac OS X, and so on.compositionAn edit UUID is a number generated on a single machine that guarantees that all machines in the same space-time are unique. Typically, the platform provides the generated APIs. According to the standard calculations developed by the Open Software Foundation (OSF), use the Ethernet card address, nanosecond time, chip ID code, and many possible digital UUID combinations of the following: (1) The current date and time, the first part of the UUID is related to time, if you are generating a UUID, When a UUID is generated in a few seconds, the first part is different and the rest is the same. (2) clock sequence. (3) Globally unique IEEE machine identification number, if there is a network card from the network card MAC address, no NIC in other ways to obtain. The only drawback to the UUID is that the resulting string will be longer. The most common use of the standard for UUID is the Microsoft GUID (Globals Unique Identifiers). In ColdFusion, the Createuuid () function can be used to easily generate a UUID in the form of: Xxxxxxxx-xxxx-xxxx-xxxxxxxxxxxxxxxx (8-4-4-16), where each x is 0-9 or a-f A hexadecimal number within the range. The standard UUID format is: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx (8-4-4-4-12), which can be converted from the Cflib Download CreateGUID () UDF.ApplicationThe benefits of editing using UUID are reflected in distributed software systems (e.g., DCE/RPC, Com+,corba), which ensures that the identities generated by each node are not duplicated, and that the advantages of the UUID will be more pronounced with the development of integrated technologies such as Web services. Depending on the specific mechanism used, the UUID needs to be not only guaranteed to be different from each other, or at least a very large difference from the universal unique identifier of any other generation before A.D. 3400. A universal unique identifier can also be used to point to most possible objects. Microsoft and other software companies tend to use globally unique identifiers (GUIDs), which are also a type of universal unique identifiers that point to Building object module objects and other software components. The first universal unique identifier is a component of the Distributed computing Environment (DCE) that was created in the network computer system (NCS) and subsequently became the Open Software Foundation (OSF).CodeEdit Java

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package  com.mytest import  java.util.UUID; publ ic  class  utest {