UUID kincolle’s blogs

The UUID is short for Universally Unique Identifier.

In java, there has 2 functions: randomUUID() and nameUUIDFromBytes(). The randomUUID() will create an UUID randomly which is always used for orderId. The nameUUIDFromBytes(byte[] n) will create an UUId according to the n, and it is always used for user checking like the identification.

Here is an example:

import java.util.UUID;
public class UuidDemo {
    public static void main(String[] args) {


        System.out.println(UUID.randomUUID().toString().replace("-", ""));
        System.out.println(UUID.randomUUID().version());

        System.out.println(UUID.nameUUIDFromBytes("890110866094329856".getBytes()).toString().replace("-", ""));
        System.out.println(UUID.nameUUIDFromBytes("890110866094329856".getBytes()).version());

    }
}

The result will be:

d9613ff9975b47e3a8bb1ef3766f7a86 
4 
873473466cf23b5fb988827f8dffbe7d 
3