java中instanceof和getClass()的区别分析

本篇文章介绍了，在java中instanceof和getClass()的区别分析。需要的朋友参考下 class A { } 

class B extends A { } 

Object o1 = new A(); 

Object o2 = new B(); 

o1 instanceof A => true 

o1 instanceof B => false 

o2 instanceof A => true // <================ HERE  o2 instanceof B => true 

o1.getClass().equals(A.class) => true 

o1.getClass().equals(B.class) => false 

o2.getClass().equals(A.class) => false // <===============HERE 

o2.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.

一个非常完美的equals方法的写法：

复制代码 代码如下:    public boolean equals(Object otherObject)    {      

// a quick test to see if the objects are identical     

  if (this == otherObject) return true;

      // must return false if the explicit parameter is null     

  if (otherObject == null) return false;

      // if the classes don't match, they can't be equal     

  if (getClass() != otherObject.getClass()) return false;

      // now we know otherObject is a non-null Employee     

  Employee other = (Employee) otherObject;

      // test whether the fields have identical values      

return name.equals(other.name) && salary == other.salary && hireDay.equals(other.hireDay);   

}

详细出处参考：http://www.jb51.net/article/36114.htm