Tracking number of objects created

[Enge Chall]

Hi,
How to track the number of objects created, of a perticular class ?
I mean without using static variables.

Qn is is there any java API which can provide the number of objects created for a perticular class ?

thanks in advance.
Chall.

[Barry Gaunt]

Does not belong in SCJP. Please keep your questions relevant to the forum.
Moving to Java In General (Intermediate).

[Jesper de Jong]

> How to track the number of objects created, of a perticular class ? I mean without using static variables.

Why do you want it specifically without using static variables? So you probably already know that it's easy with a static member variable.

> Qn is is there any java API which can provide the number of objects created for a perticular class ?

No. The JVM has a debugger API which you can use to monitor a JVM and probably there's also a way to find out how many objects of a specific type the JVM has created, but there's no easy way.

[Enge Chall]

I was wondering if there is any Java Reflection API which solves the purpose. So that in the run time a programmer can code to limit the object creation.

[Tony Morris]

Originally posted by Enge Chall:
Hi,
How to track the number of objects created, of a perticular class ?
I mean without using static variables.

Qn is is there any java API which can provide the number of objects created for a perticular class ?

thanks in advance.
Chall.

Everything is possible without static variables. In fact, the very notion of "class-scoped" data is an abstraction leak. The question you might want is "how do I provide global access to some shared piece of information, such as number of instances?" This would require you to pass a callback instance to all constructors. There are many related side issues to this common question, but I'll leave those for you to explore.

[Stan James]

Can you force all clients to create instances only through a factory? The factory can keep count of how many it makes. Of course the factory wants to be a singleton so we probably have at least one static variable somewhere. Was this an academic exercise to do it with no statics at all?