hi friend,

You can write a program for getting the factorial of a given number as follows

class Factorial
{
     public static void main(String[] args)
       {
         int a= 5;
           int fact= 1;
         System.out.print("Factorial of " +a+ " = ");   
           int i = 1;
           while(i <= 5)
            {
                fact = fact*i;
                i++;
            }
           System.out.println(fact);
       }
}

For detail tutorial you can go through the following link Write a program to calculate factorial of any given number