Java - java.util.UUID

 UUID，Universally Unique Identifier，通用唯一識别碼

public class TestUUID {

	public static void main(String[] args) {
		
		String mUUID = java.util.UUID.randomUUID().toString();
		System.out.println(mUUID);  
		// 9528f93c-c85f-41d7-90d0-6003f2664086
		
		System.out.println(mUUID.replace("-", ""));
		// 9528f93cc85f41d790d06003f2664086
	
	}
	
}
           

UUID 的字元串表示形式由此 BNF 描述：

UUID                   = <time_low> "-" <time_mid> "-"
                           <time_high_and_version> "-"
                           <variant_and_sequence> "-"
                           <node>
  time_low               = 4*<hexOctet>
  time_mid               = 2*<hexOctet>
  time_high_and_version  = 2*<hexOctet>
  variant_and_sequence   = 2*<hexOctet>
  node                   = 6*<hexOctet>
  hexOctet               = <hexDigit><hexDigit>
  hexDigit               =
        "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"
        | "a" | "b" | "c" | "d" | "e" | "f"
        | "A" | "B" | "C" | "D" | "E" | "F"