java，

java，

interface C{}

class C1 implements C{}

public class C2 extends C1{
       public static void main(String[] args) {

        C c = new C1();

        System.out.println(C2.class.isInstance(c));
        System.out.println(c instanceof C2);
        System.out.println(c.getClass().isAssignableFrom(C2.class));
        System.out.println(c.getClass() == C.class);
        System.out.println(c.getClass().equals(C.class));

    }
}