How to set up a Random random = random java code example

Example 1: generate random number in java

import java.lang.Math;

int randomNumber;

int minimum = 1;
int maximum = 10 - minimum;

randomNumber = (int)((Math.random()*maximum) + minimum);

System.out.println("Random Number (Between 1-10): " + randomNumber);

Example 2: random number generator java

import java.util.Random;
class GenerateRandom {
    public static void main( String args[] ) {
      Random rand = new Random(); //instance of random class
      int upperbound = 25;
        //generate random values from 0-24
      int int_random = rand.nextInt(upperbound); 
      double double_random=rand.nextDouble();
      float float_random=rand.nextFloat();
      
      System.out.println("Random integer value from 0 to" + (upperbound-1) + " : "+ int_random);
      System.out.println("Random float value between 0.0 and 1.0 : "+float_random);
      System.out.println("Random double value between 0.0 and 1.0 : "+double_random);
    }
}