Referencia en el operador igual de Java

public class Demo{
    public static void main(String[] arr){
        Integer num1 = 100;
        Integer num2 = 100;
        Integer num3 = 500;
        Integer num4 = 500;
          
        if(num1==num2){
            System.out.println("num1 == num2");
        }
        else{
            System.out.println("num1 != num2");
        }
        if(num3 == num4){
            System.out.println("num3 == num4");
        }
        else{
            System.out.println("num3 != num4");
        }
    }
}
Clear Cow