How to implement boxing and unboxing in my own class?

问题

In Java there is no operator overriding like i C++ so I can't figure out how to implement a boxing/unboxing for my own class.

For example it's possibile to use boxing and unboxing with Integer or Float when we do somethings like this:

int myVar = new Integer(25);

But how can I implement something similar in my class MyObject? (in the case I want to wrap a primitive type myself). Is there any code example?

回答1:

There is no way to implement auto-boxing and auto-unboxing for a user-defined class.

You can of course provide named methods to do the job. However, you would have to call them explicitly every time you need to box or unbox something.

回答2:

autoBoxing or unboxing is available only with primitive in java like Long wrapper class for long

Integer for int

but user defiend not possible,

best you can do constructor initialize like

Myclass m=new Myclass(100);

回答3:

It's not possible to implement automatic boxing and unboxing for your own class - auto(un)boxing is a language feature, implemented in the Java compiler.

来源：https://stackoverflow.com/questions/15919475/how-to-implement-boxing-and-unboxing-in-my-own-class