UUID is the abbreviation of Universally Unique Identifier, a standard for software construction, and also Part of the Open Software Foundation organization in the field of distributed computing environments. UUID is a 128-bit value that can be calculated by a certain algorithm. For efficiency, commonly used UUIDs can be shortened to 16 bits. UUID is used to identify the attribute type and is regarded as a unique identifier in all space and time. In general, any UUID generated anywhere where this value is guaranteed to be truly unique will not have the same value. One benefit of using UUIDs is that new identifiers can be created for new services. The standard UUID format is：xxxxxxxx-xxxx-xxxx-xxxxxx-xxxxxxxxxx(8-4-4-4-12)。