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How can generate absolute unique number without using complicated math functions

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Question: How can I generate absolute unique number without using complicated math functions? Not pseudo random from Java API...

I do not need it for high security; I need to have a unique Id for database connection...

Answer: Combine any of the following:

  • IP address
  • process id
  • random number (from Java API)
  • Date(month,day,year)
  • Time(hour,minute,second, millisecond) and then put them together like this:


You can also put them in different order each time when you do it


//Here just simplest example on random() usage..
//Real working code is up to you :-)
public class RandomNumbers {

    private static void doRawRandomNumber() {

        double rawRandomNumber;

        rawRandomNumber = Math.random();
        System.out.println("Raw random number : " + rawRandomNumber);

     * Sole entry point to the class and application.
     * @param args Array of String arguments.
    public static void main(String[] args) {


Some another Java code examples for Math.random() you can find here

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