對(duì)象 instanceof 類名，表示 對(duì)象是類名的實(shí)例，或者是其子類的實(shí)例，返回 true，否則返回 false。

對(duì)象.getClass() == 類名.class ，表示 只有對(duì)象是該類的實(shí)例，才返回 true

class A { }class B extends A { }Object o1 = new A();Object o2 = new B();o1 instanceof A => trueo1 instanceof B => falseo2 instanceof A => true // <================ HEREo2 instanceof B => trueo1.getClass().equals(A.class) => trueo1.getClass().equals(B.class) => falseo2.getClass().equals(A.class) => false // <===============HEREo2.getClass().equals(B.class) => true getClass() will be useful when you want to make sure your instance is NOT a subclass of the class you are comparing with.

例子：

class Base{ }class Derived extends Base{ }public class Hello { public static void main(String[] args) throws ParseException { Derived d = new Derived(); boolean bRet; bRet = d instanceof Derived;//true bRet = d instanceof Base;//true bRet = d.getClass() == Derived.class;//true// bRet = d.getClass() == Base.class;// 出錯(cuò) bRet = d.getClass().equals(Base.class);//false }}

使用，重寫equals

class Person{ private String id; private String name; //重寫equals()方法，提供自定義的相等標(biāo)準(zhǔn) public boolean equals(Object obj){ if(this == obj)//若為同一個(gè)對(duì)象 return true; //只有當(dāng)obj是Person對(duì)象 if(null != obj && obj.getClass() == Person.class){ Person p = (Person)obj; if(id.equals(obj).getId() && ...){return true; } } return false; }}

以上就是本文的全部內(nèi)容，希望對(duì)大家的學(xué)習(xí)有所幫助，也希望大家多多支持好吧啦網(wǎng)。