Java中检查对象类型的不同方法？

Question

I have an object obj and a class name MyClass , i can check whether obj is of the type MyClass using either instanceof or i can say obj.getClass().equals("MyClass"). So i want to know are there any other ways of checking the type of an object.

Answer 1

Note that the two options you cite are not equivalent:

"foo" instanceof Comparable // returns true
"foo".getClass().equals(Comparable.class) // return false

Answer 2

Beware: instanceof returns true also if your object is a subclass of MyClass , or if it implements the interface (this is usually what you are interested in - if you recall the "IS A" OOP concept)

See also this about Class.isAssignableFrom() , similar to instanceof but a little more powerful.

Answer 3

Class＃isAssignableFrom（java.lang.Class）是另一种选择。

Answer 4

instanceof是另一种选择。

Answer 5

instancef is not proper solution as it gives true for subclass of a class. Use this instead:

 obj.getClass().equals("MyClass")

Answer 6

您可能可以通过obj.getClass().getSuperClass()递归来获得类似于instanceof东西。

Answer 7

As said by others, instanceof does not have the same functionality as equals .

On another point, when dealing with this problem in code, using a Visitor -pattern is a clean (although not smallest in lines of code) solution. A nice advantage is that once a visitor-interface has been setup for a set of classes, this can be reused again in all other places that need to handle all/some/one different extensions of a class.