Perfect number assistance

Question

Hello,
I'm currently enrolled in a JAVA course and doing very horrible. This course is required for my degree. I have been reviewing the forums and got this far on a program that will ask the user to enter a number and this program will find all the perfect numbers less then the number entered by the user. Here is the code I have so far. Any assistance would be greatly appreciated.
import java.util.Scanner;
public class Stalcup_Robert_6_01_perfect
{//Begin Class
public static void main (String[ ] args)
{//Begin main method
          int testNum;     
          //Create a scanner object for keyboard input
          Scanner keyboard = new Scanner(System.in);
          //Recieve keyboard entry
          System.out.println("Please enter in any number?");
          //Hold keyboard entry
          testNum = keyboard.nextInt();
     }//End Main methhod
     public static void factorSum()
          int num=1, testNum, elements=0, sum=0, p=0, sum1=0, sum2=0, factors, PrimeNumSequence;
          while (num < testNum)
               for(int a = 1; a<num; a++)
                    if(num % a == 0) factors[p++] = a;
               int[] factors = new int[elements];
               for(int a = 1; a<num; a++)
                    if(num % a == 0) factors[p++] = a;
               for(int a=0; a < factors.length; a++)
                    if(PrimeNumSequence.isPrime(factors[a]) && factors[a] > 2)
                         sum1 = factors[a] * factors[a-1];
                         sum2 = factors[a-1] * 2;
                         sum2 = sum2 - 1;
                    if(sum1 == num && sum2 == factors[a])
                    System.out.println(num + " is a perfect number of " + testNum);
}//End Class

Answer 1

I think what you want to do is to use a recursive method to find out the UNIQUE factors of a number smaller than the given. then check if it is a perfect number. I am thinking you can use either a set or array to collect the factors, then get the sum of the set or array and compare the sum with the number that was factored.
     private static Set<Integer> A = new HashSet<Integer>();
     public static void primeFactors(int num)
          int d;
         if (num > 1)
              for (d = 2; (num % d) > 0; d++);          
                       A.add(d);
                primeFactors(num / d);
     }