Palindromic Prime - Combining isPrime and isPalindrome

Hi guys I am somewhat new to Java programming and am looking for some help. I have 2 programs, isPrime and isPalindrome, and I would like to combine them so that the new program displays the first 100 prime numbers that are palindromes. I am having a hard time doing this and was wondering if anyone could help me. Thanks

isPrime Code:

Code:

---

public class ShowPrimes
{
        static final int TOTAL_PRIMES_TO_FIND = 100;        // number of primes to be found in this application
        static final int PRIMES_SHOWN_PER_LINE = 10;        // number of primes shown per display line       
       
        public static void main(String[] args)
        {
                int lastPrimeFound;                                // last prime number found via test
                int count;                                                // count of number of primes found
               
                System.out.println("Here are the first 100 prime numbers:  ");
                System.out.printf("%5d%5d", 2,3);        // clearly  2 and 3 are  prime numbers!
                lastPrimeFound = 3;                                                // our first number to test
               
                for (count = 2; count < TOTAL_PRIMES_TO_FIND; )
                {
                        ++count;                                                                                        // count of the prime we are presently finding
                        lastPrimeFound = getNextPrime(lastPrimeFound);                // candidate for next prime from previous prime
                        System.out.printf("%5d", lastPrimeFound);                        // prime found, so display it
                        if (count % PRIMES_SHOWN_PER_LINE == 0)
                                System.out.printf("\n");       
                }
        }

        // returns the next prime number using value of primeJustFound to generate a next candidate
       
        private static int getNextPrime(int primeJustFound)
        {
                int candidate;                // candidate value tested for a prime
               
                candidate = primeJustFound + 2;
                while (!isPrime(candidate))
                {
                        candidate += 2;
                }
               
                return candidate;
        }
        // returns true if testValue is prime and false if testValue is divisible by some number other than 1 or itself
               
        private static boolean isPrime(int possiblePrime)
        {
                boolean factorFound = false;                                // set to true if loop finds a factor
                double limit = Math.sqrt(possiblePrime);        // upper limit on integers to test       
                int possibleFactor;                                                        // int value that could be a factor of possiblePrime
               
                possibleFactor = 3;                                                                // even numbers are not part of the logic
                while (possibleFactor <= limit && !factorFound)        // exits with factor found or no more factors to test
                {
                        if (possiblePrime % possibleFactor == 0)        // factor found; no longer prime
                                factorFound = true;
                        else
                                possibleFactor+= 2;
                }
               
                return !factorFound;
        }       
}

---

isPalindrome Code:

Code:

---

import java.util.*;

// Main is a driver for the method isPalindrome

public class TestIsPalindrome
{
        static Scanner keyboard = new Scanner(System.in);
       
        public static void main(String[] args)
        {
                int testValue;
               
                System.out.print("Enter a test value:  ");
                testValue = keyboard.nextInt( );
                keyboard.nextLine( );

                if (isPalindrome(testValue))
                        System.out.println("The number " + testValue + " is a palindrome.");
                else
                        System.out.println("The number " + testValue + " is not a palindrome.");                               
        }

        // returns true if testValue is a palindrome; otherwise returns false
       
        private static boolean isPalindrome(int testValue)
        {
                int reversedNumber;                                // least significant digit of testValue is most significant and vice-versa
                int generatorForReversedNumber;        // gotten by "extracting" and weighting each digit from testValue
                int nextDigit;                                        // to be extracted from testValue
               
                reversedNumber = 0;                                // sum accumulator.. initially no digits accumulated
                generatorForReversedNumber = testValue;
                while (generatorForReversedNumber > 0)
                {
                        nextDigit = generatorForReversedNumber % 10;
                        reversedNumber = 10 * reversedNumber + nextDigit;
                        generatorForReversedNumber /= 10;
                }
               
                return testValue == reversedNumber;
        }
}

---

how would I go about combining them? I tried changing up the main but still doesn't work.

Could you call one method and if it returns true, then call the other?

not sure how to do that. could you demonstrate?

Method to check if a number is a palindrome

Code:

---

public boolean isPalindrome(int number) {
  //code to find out if it is a palindrome
  ... //if it is a palindrome, return true;
  //otherwise:
  return false;
}

---

The part of your code where you are checking for both palindrome and prime

Code:

---

List<Integer> listOfPrimes = getANumberOfPrimes(100);
for (int prime:listOfPrimes) {
    if (isPalindrome(prime)) {
        //it is both a palindrome and a prime
        ...
    }
}

---

Method to get a number of primes

Code:

---

public List<Integer> getANumberOfPrimes(int number) {
    ...
}

---

while count < 100
get next prime
is it a palindrome?
save it and incr the count
end loop