Multi-threading same code at the same time

Question

I want my program to test two BigIntegers at the same time. As of now my code is testing one at a time. Since I want the code to be the same for both runs, is there a simple synchronized statement that I would be able to use to implement this?

 public static void main(String[] args) {
    String input = JOptionPane.showInputDialog("Enter number ");
    int number = Integer.parseInt(input);
    BigInteger num = new BigInteger(input);

    String output = num + " is" + (IsPrime(num) ? " " : " not ")
            + "a prime number.";

    JOptionPane.showMessageDialog(null, output);
}   
public static boolean IsPrime(BigInteger num) {
    if (num.mod(new BigInteger("2")).compareTo(BigInteger.ZERO) == 0) {
      return false;
    for (BigInteger i = new BigInteger("3"); i.multiply(i).compareTo(num) <= 0; i =
        i.add(new BigInteger("2"))) {
      if (num.mod(i).compareTo(BigInteger.ZERO) == 0) {
       return false;
      }
    }
    return true;
  }
}

Answer 1

I have reached a solution to my question.

Because two integers were being tested I needed to create a textOne and a textTwo to test each individually for primeness.

 public static boolean IsPrime(BigInteger textOne) {
    // check if number is a multiple of 2
    if (textOne.mod(new BigInteger("2")).compareTo(BigInteger.ZERO) == 0) {
      return false;
    }// if not, then just check the odds
    for (BigInteger i = new BigInteger("3"); i.multiply(i).compareTo(textOne) <= 0; i =
        i.add(new BigInteger("2"))) {
      if (textOne.mod(i).compareTo(BigInteger.ZERO) == 0) {

       return false;
      }
    }
    return true;
}   
public static boolean IsPrime2(BigInteger textTwo) {
    // check if number is a multiple of 2
    if (textTwo.mod(new BigInteger("2")).compareTo(BigInteger.ZERO) == 0) {
      return false;
    }// if not, then just check the odds
    for (BigInteger i = new BigInteger("3"); i.multiply(i).compareTo(textTwo) <= 0; i =
        i.add(new BigInteger("2"))) {
      if (textTwo.mod(i).compareTo(BigInteger.ZERO) == 0) {

       return false;
      }
    }
    return true;
}

I designated that num and num2 be designated for the BigIntegers so that output would reflect the following..

public void run() {

    String output = num + " is" + (IsPrime(num) ? " " : " not ")
            + "a prime number.";
    lblResults.setText(output);

    String output2 = num2 + " is" + (IsPrime(num2) ? " " : " not ")
            + "a prime number.";
    lblResults2.setText(output2);
}}