public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        String password = "olav2009";
        // Contains at least one letter between a-z and one letter between 0-9
        System.out.println("Regex way: " + password.matches("[a-z]*{1}[0-9]*{1}"));

        char[] charArray = password.toCharArray();

        boolean isValid = false;
        for(int i = 0; i< charArray.length; i++){
            if(Character.isLetterOrDigit(charArray[i])){
                isValid = true;
                break;
            }
        }
        System.out.println("Complicated way: "+isValid);
    }

}