Java 8 Solution:-

import java.io.*;
import java.util.*;

interface PerformOperation {
    boolean check(int a);
}

class MyMath {
    public static boolean checker(PerformOperation p, int num) {
        return p.check(num);
    }

    public PerformOperation isOdd() {
        return a -> a % 2 != 0;
    }

    public PerformOperation isPrime() {
        return a -> {
            if (a <= 1)
                return false;
            if (a == 2 || a == 3)
                return true;

            if (a % 2 == 0 || a % 3 == 0)
                return false;

            for (int i = 5; i <= Math.sqrt(a); i = i + 6)
                if (a % i == 0 || a % (i + 2) == 0)
                    return false;
            return true;

        };
    }

    public PerformOperation isPalindrome() {

        return a -> {
            String s = "" + a;
            int i = 0, j = s.length() - 1;

            while (i < j) {
                if (s.charAt(i) != s.charAt(j)) {
                    return false;
                }
                i++;
                j--;
            }
            return true;
        };
    }


}


// Write your code here

public class Solution {

    public static void main(String[] args) throws IOException {
        MyMath ob = new MyMath();
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int T = Integer.parseInt(br.readLine());
        PerformOperation op;
        boolean ret = false;
        String ans = null;
        while (T-- > 0) {
            String s = br.readLine().trim();
            StringTokenizer st = new StringTokenizer(s);
            int ch = Integer.parseInt(st.nextToken());
            int num = Integer.parseInt(st.nextToken());
            if (ch == 1) {
                op = ob.isOdd();
                ret = ob.checker(op, num);
                ans = (ret) ? "ODD" : "EVEN";
            } else if (ch == 2) {
                op = ob.isPrime();
                ret = ob.checker(op, num);
                ans = (ret) ? "PRIME" : "COMPOSITE";
            } else if (ch == 3) {
                op = ob.isPalindrome();
                ret = ob.checker(op, num);
                ans = (ret) ? "PALINDROME" : "NOT PALINDROME";

            }
            System.out.println(ans);
        }
    }
}

My solution:

interface Predicate{

boolean test(int a);

} public class Solution {

public static void main(String[] args) {

    Scanner scan = new Scanner(System.in);
    int full = scan.nextInt();
    while(full--> 0){
        int code = scan.nextInt();
        int number = scan.nextInt();
        if (code==1){
            boolean a = op(n-> isOdd(n), number);
        System.out.println(a==true?"EVEN":"ODD");
        }else if(code==2){
               boolean a = op(n-> isPrime(n), number);
        System.out.println(a==true?"PRIME":"COMPOSITE");
        }else{
               boolean a = op(n-> isPalindrome(n), number);
        System.out.println(a==true?"PALINDROME":"NOT PALINDROME");
        }
    }
}
static boolean op(Predicate<Integer> predi, int number) {
    return predi.test(number);

}
static boolean isPrime(int number) {
    for(int i=2;i<(int)Math.sqrt(number);i++){
        if(number%i==0) return false;
    }
    return true;
}
static boolean isPalindrome(int number) {
    String c = ""+number;
    StringBuilder b = new StringBuilder(c).reverse();
    int d = Integer.parseInt(b.toString());
    return number==d;
}

static boolean isOdd(int number) {
    return number%2==0;
}

}

this is the easy solution without making more method in the class mymath //**************** import java.io.; import java.util.;

public class Solution {

public static void main(String[] args) throws IOException {
    MyMath ob = new MyMath();
    Scanner br = new Scanner(System.in);
    int T = Integer.parseInt(br.nextLine());
    PerformOperation op;
    boolean ret = false;
    String ans = null;
    while (T--> 0) {
        String s = br.nextLine().trim();
        String[] st = s.split("\\s");
        int ch = Integer.parseInt(st[0]);
        int num = Integer.parseInt(st[1]);
        if (ch == 1) {
            op = (a) -> {return a % 2 != 0;};
            ret = ob.checker(op, num);
            ans = (ret) ? "ODD" : "EVEN";
        } else if (ch == 2) {
            op = (a) -> {
                    if (a < 2) {
                        return false;
                    } else if (a == 2) {
                        return true;
                    } else if (a % 2 == 0) {
                        return false;
                    }
                    int sqrt = (int) Math.sqrt(a);
                    for (int i = 3; i <= sqrt; i += 2) {
                        if (a % i == 0) {
                            return false;
                        }
                    }
                    return true;
                    };
            ret = ob.checker(op, num);
            ans = (ret) ? "PRIME" : "COMPOSITE";
        } else if (ch == 3) {
            op = a -> {
                    String str = String.valueOf(a);
                    int start = 0;
                    int end = str.length() - 1;
                    while (start < end) {
                        if (str.charAt(start) != str.charAt(end)) {
                            return false;
                        }
                        start++;
                        end--;
                    }
                    return true;
                };
            ret = ob.checker(op, num);
            ans = (ret) ? "PALINDROME" : "NOT PALINDROME";

        }
        System.out.println(ans);
    }
    br.close();
}

}

@FunctionalInterface interface PerformOperation { boolean check(int a); } class MyMath { public boolean checker(PerformOperation p, int num) { return p.check(num); } }

`

This problem isn't specitic enough. I don't know what it wants me to do. I literally don't know what the problem is asking. A lot of the problems in this section "Java" are very specific, and do a great job to introduce new concepts, so that's what I expect. Furthermore, I do not understand the code. There is an interface that has not been implemented, then another class called "MyMath" that calls methods from that interface? If I don't understand how this code even works, how am I supposed to complete it? If I have never used a Lambda expression in my life, I should be able to read the problem, do a bit of research, then solve it.

The problem description should be more specific, especially about returned output for a case when a number is not a palindrome, it looks that expected text then is "NOT PALINDROME". It also looks that test cases contain only some small numbers and algorithms do not have to be efficient.