No main class found - Netbeans

Question

I know that there are many other topics on this issue, and I have read many, many of them and none seem to help. I am new to Java and so I feel that maybe I am missing something simple. If I use "Clean and Build" no errors, but as soon as I attempt to run or debug the code, I am given a "No main class found."

If I change the "Public Void Main" and "Public Void IsPrime" to include "Static", then I am given "non-static variable factor cannot be referenced from a static context" errors.

Can anyone provide any guidance?

public class LargestPrime {

/**
 *
 */
public long factor;
 /**
 * @param args the command line arguments
 */
public static void main(String[] args){
    double var, sqvar;
    var = 600851475143L;
    sqvar = Math.sqrt(var);
    ArrayList<Long> factors = new ArrayList<>();
    long i = 1;

    while(i <= sqvar){
        if (var % i == 0){
            if(i % 2 != 0 ){
                factors.add(i);
            }
        }
        i = i + 2;
    }

    ArrayList<Long> primes = new ArrayList<>();

    int j;
    for(j = 0; j <= factors.size(); j++){
        factor = factors.get(j);
        LargestPrime obj = new LargestPrime();
        obj.isPrime(factor);
    }

}

/**
 *
 * @param testing
 *
 */
public static void isPrime(long testing){
    testing = factor;
    System.out.println(testing);
}
 }

Answer 1

Try to change the factor variable to a static like this public static long factor; variable.
And replace this for loop:

   for(j = 0; j <= factors.size(); j++){

With using < instead of <= because the size of ArrayList from 0 to size-1:

 for(j = 0; j < factors.size(); j++){