(Twin primes) Twin primes are a pair of prime numbers that differ by 2. For example, 3 and 5 are twin primes, 5 and 7 are twin primes, and 11 and 13 are twin primes. Write a program to find all twin primes less than 1,000. Display the output as follows:

/*
(Twin primes) Twin primes are a pair of prime numbers that differ by 2. For example,
3 and 5 are twin primes, 5 and 7 are twin primes, and 11 and 13 are twin primes.
Write a program to find all twin primes less than 1,000. Display the output as follows:
(3, 5)
(5, 7)
...
*/
public class Exercise_06_29 {
	/** Main Method */
	public static void main(String[] args) {
		// Find  and display all twin primes less than 1,000
		System.out.println();
		for (int p = 2; p < 1000; p++) {
			if (isTwinprime(p))
				System.out.println("(" + p + ", " + (p + 2) + ")");
		}
	}

	/** Method isTwinprime returns true if num and num + 2 are primes */
	public static boolean isTwinprime(int num) {
		return PrimeNumberMethod.isPrime(num) && PrimeNumberMethod.isPrime(num + 2);
	}
}

PrimeNumberMethod.java 

public class PrimeNumberMethod {
	public static void main(String[] args) {
		System.out.println("The first 50 prime numbers are \n");
		printPrimeNumbers(50);
	}

	public static void printPrimeNumbers(int numberOfPrimes) {
		final int NUMBER_OF_PRIMES_PER_LINE = 10; // Display 10 per line
		int count = 0; // Count the number of prime numbers
		int number = 2; // A number to be tested for primeness

		// Repeatedly find prime numbers
		while (count < numberOfPrimes) {
			// Print the prime number and increase the count
			if (isPrime(number)) {
				count++; // Increase the count
			
				if (count % NUMBER_OF_PRIMES_PER_LINE == 0) {
					// Print the number and advance to the new line
					System.out.printf("%-5s\n", number);
				}
				else
					System.out.printf("%-5s", number);
			}
	
			// Check whether the next number is prime
			number++;
		}
	}

	/** Check whether number is prime */
	public static boolean isPrime(int number) {
		for (int divisor = 2; divisor <= number/2; divisor++) {
			if (number % divisor == 0) { // If true, number is not prime
				return false; // Number is not a prime
			}
		}

		return true; // Number is prime
	}
}