A year is a leap year if it is divisible by 4. But if the year is divisible by 100, it is a leap year only when it is also divisible by 400.

import java.util.Scanner;

public class LeapYear {

    public static void main(String[] args) {
        Scanner reader = new Scanner(System.in);
        System.out.print("Type a year: ");
        int year = Integer.parseInt(reader.nextLine());
        int leap1 = year % 4;
        int leap2 = year % 100;
        int leap3 = year % 400;
        if (leap1 == 0 || ((leap2 == 0) && (leap3 == 0))) {
            System.out.println("The year is a leap year.");
        } else {
            System.out.println("The year is not a leap year");
        }

    }
}