core classes still need to be declared final?

[cowwoc]

	My understanding is that this has nothing to do with performance. 
Certain classes, such as String, as declared final for security reasons.

	In the case of Integer I would suggest using composition. It's not as 
nice but it'll work.

Gili

Nick Radov wrote:
> 
> Is it still necessary for the core Java classes such as 
> java.lang.Integer to be declared final? I understand that may have been 
> necessary in the early days for performance reasons, but modern JVMs no 
> longer provide much of a performance benefit for final classes. For 
> certain applications it would really be helpful to be able to subclass 
> some of those core classes.
> 
> For example, one application I'm working on deals with integer values 
> that must be between 0 and 9999 inclusive. I would like to be able to 
> create a custom Integer subclass which enforces that limit in the 
> constructor, but currently that isn't possible. While I could create a 
> new class that acts as a wrapper around Integer, the syntax would be 
> much more awkward and that would also make it much more difficult to 
> interface with other third-party classes.
> 
> *Nick Radov | Research and Development Manager | Axolotl Corp*
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