find and print n prime numbers in java code example

Example 1: java prime numbers

public class Main {
  public static void main(String[] args) {
    for (int i = 2; i < 1_000_000; ++i) {
      boolean isPrime = true;
      int sqrt = (int)Math.ceil(Math.sqrt(i));
      for (int divisor = 2; divisor <= sqrt; ++divisor) {
        if (i % divisor == 0) {
          isPrime = false;
          break;
        }
      }
      if (isPrime) {
        System.out.println(i);
      }
    }
  }
}

Example 2: Java program to print prime numbers in a given range

// Java program to print prime numbers in a given range
public class PrimeNumberRangeDemo 
{
   public static void main(String[] args) 
   {
      int lowerRange = 10, higherRange = 50;  
      while(lowerRange < higherRange) 
      {
         boolean flag = false;
         for(int a = 2; a <= lowerRange / 2; ++a) 
         {
            if(lowerRange % a == 0)
            {
               flag = true;
               break;
            }
         }
         if(!flag && lowerRange != 0 && lowerRange != 1)
             System.out.print(lowerRange + " ");
         ++lowerRange;
      }
   }
}