Java中isAssignableFrom的用法

package com.auuzee.test1;class A {}class B extends A {}public class Test1 {    public static void main(String[] args) {        A a = new A();        B b = new B();        A ba = new B();        System.out.println("1-------------");        System.out.println(A.class.isAssignableFrom(a.getClass()));        System.out.println(B.class.isAssignableFrom(b.getClass()));        System.out.println(A.class.isAssignableFrom(b.getClass()));        System.out.println(B.class.isAssignableFrom(a.getClass()));        System.out.println(A.class.isAssignableFrom(ba.getClass()));        System.out.println(B.class.isAssignableFrom(ba.getClass()));        System.out.println("2-------------");        System.out.println(a.getClass().isAssignableFrom(A.class));        System.out.println(b.getClass().isAssignableFrom(B.class));        System.out.println(a.getClass().isAssignableFrom(B.class));        System.out.println(b.getClass().isAssignableFrom(A.class));        System.out.println(ba.getClass().isAssignableFrom(A.class));        System.out.println(ba.getClass().isAssignableFrom(B.class));        System.out.println("3-------------");        System.out.println(Object.class.isAssignableFrom(b.getClass()));        System.out.println(Object.class.isAssignableFrom("abc".getClass()));        System.out.println("4-------------");        System.out.println("a".getClass().isAssignableFrom(Object.class));        System.out.println("abc".getClass().isAssignableFrom(Object.class));    }}