Buscando los números primos, en Java

package DelDia;

public class BuscandoAlPrimo {

	public static void main(String[] args)
	{
		System.out.println("INICIO");
		double limite = 100000;
		for (double numero=2.0; numero<=limite; numero++)
		{
			int nPrimos = 1;
			for (int divisor=2; divisor <= (numero); divisor++)
			{
				if ((numero % divisor) == 0)
				{
					nPrimos++;
				}
			}
			// fin de la comprobacion :P
			if (nPrimos==2){
				System.out.println("Se encontro:  " + numero);				
			}
		}
		System.out.println("FIN :P ");

	}

}

package mathio;

import java.util.*;
import java.util.concurrent.CopyOnWriteArrayList;

/**
 * Math util methods and classes
 * @author Gustavo Garsaky
 * @version 0.0.1
*/
public class MathUtils {
	
	public PrimeNumbers primeNumbers() {
		return new PrimeNumbers();
	}
	
	private class PrimeNumbers {
		
		public List<Integer> listPrimesUntil(int limit) {
			List<Integer> naturals = new CopyOnWriteArrayList<>();
			// init naturals
			for(int i=2; i<=limit; i++) {
				naturals.add(i);
			}
			for(Integer current : naturals) {
				discardMultiples(naturals, getMultiplesOf(current, naturals.size()));
				// if discard continue, that means the process should continue
				if(discard(current, naturals.size())) {
					continue;
				} else {
					break;
				}
			}
			List<Integer> primes = naturals;
			return primes;
		}
		/**
		 * check the first natural quad. If it's
		 * less tan limit, process should continue
		 * @param firstNatural first natural number
		 */
		private boolean discard(int firstNatural, int limit) {
			double firstNaturalQuad = Math.pow(new Double(String.valueOf(firstNatural)), 2.0d);
			if(firstNaturalQuad <= limit) {
				return true;
			}
			return false;
		}
		/**
		 * Get new list of natural numbers. The new list have all numbers
		 * that not in multiples of first natural number
		 * @param naturals Naturals numbers
		 * @param number Number to get multiples
		 */
		private void discardMultiples(List<Integer> naturals, List<Integer> multiples) {
			// check if each multiple is in naturals list.
			// if it isn't, append the multiple to new list 
			for(int i=0; i<multiples.size(); i++) {
		             for(int k=0; k<naturals.size(); k++) {
         	                 if(multiples.get(i) == naturals.get(k)) {
		                     naturals.remove(k); 
                                  }
		             }    
			}    
		 }
	} // end private class
	
	
	/**
	 * Get the multiples of a number with some limit
	 * @param number Number to get multiples
	 * @param limit of multiples to get
	 */
	public static List<Integer> getMultiplesOf(int number, int limit) {
		List<Integer> multiples = new ArrayList<>();
		for(int i=number; i<limit; i++ ) {
			if(i < limit) {
				multiples.add(number * i);
			}
		}
		return multiples;
	}
	public static void main(String[] args) {
		PrimeNumbers primeNumbers = new MathUtils().primeNumbers();
		List<Integer> primes = primeNumbers.listPrimesUntil(100);
   		System.out.println("[+] Listando numeros primos...\n");
		for(Integer prime : primes) {
			System.out.println(prime);
		}
	}
}