Palindrome Number

Solving Code

public class Palindrome {
    public boolean isPalindrome(int x) {
        if (x < 0) return false;
        if (x != 0 && x % 10 == 0) return false;
        int reverse = 0;
        while (x > reverse) {
            int lastDigit = x % 10;
            reverse = reverse * 10 + lastDigit;
            x = x / 10;
        }
        return (x == reverse) || (x == reverse / 10);
    }
}

Test Code (JUnit)

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class PalindromeTest {
    private final Palindrome palindrome = new Palindrome();

    @Test
    void testSimpleIsPalindrome() {
        assertTrue(palindrome.isPalindrome(12321));
    }

    @Test
    void testFalseIsPalindrome() {
        assertFalse(palindrome.isPalindrome(12312));
    }

    @Test
    void testOnlyZero() {
        assertTrue(palindrome.isPalindrome(0));
    }

    @Test
    void testTen() {
        assertFalse(palindrome.isPalindrome(10));
    }
}