Java: Check if Number is a Prime Number

Java Number Primality Check.java

	/**
	 * Checks the primality of the given number. 
	 * Prime numbers can be used in password encryptions
	 * and cryptography.
	 * 
	 * Basically, a prime number is:
	 * 1. A whole number which is greater than 1 
	 * 2. And can only be divided evenly by 1 
	 *    and the number itself.
	 * 
	 * @param number
	 * @author Jon Bonso
	 * @return boolean
	 */
	static boolean isPrimeV2(int number) {
		
		if (number <= 1)
			return false;
		
		if (number == 2)
			return true;
		
		if ((number % 2) == 0)
			return false;
		
		for (int i=3; i < (number/2); i=i+2) {
			if ( (number % i) == 0 )
				return false;
		}
		
		return true;
	}
	
	/**
	 * Checks if the input is a prime number
	 * using BigInteger.isProbablePrime() method
	 * that implements Miller-Rabin primality tests
	 * @param input
	 * @author Jon Bonso
	 * @return
	 */
	static boolean isPrime(int input) {
		BigInteger bigInt = BigInteger.valueOf(input);
		// Sets the probability to 100 to make it a "certainty"
		return bigInt.isProbablePrime(100);
	}
	
	public static void main(String... args) {
		
		System.out.println( isPrime(1) );
		System.out.println( isPrime(2) );
		System.out.println( isPrime(3) );
		System.out.println( isPrime(5) );
		System.out.println( isPrime(9) );
		
		System.out.println( isPrime(10) );
		System.out.println( isPrime(11) );
		System.out.println( isPrime(12) );
		System.out.println( isPrime(13) );
		System.out.println( isPrime(15) );
    
	}