Re: Reflection: Instantiate All Classes in a Package?

From:

Joshua Cranmer <Pidgeot18@epenguin.zzn.com>

Newsgroups:

comp.lang.java.programmer

Date:

Sun, 25 Mar 2007 20:43:11 GMT

Message-ID:

<z9BNh.2213$Qi2.1850@trndny07>

Chris Uppal wrote:

Joshua Cranmer wrote:

In summary: Yes, one can get a list of classes in a certain package
through various means, but no, it cannot be done through /pure/
reflection. Happy now?

No, It can be done through nothing more than pure reflection (using only
ClassLoader.findClass() as exposed via Class.forName(String, ClassLoader))
Read the thread that Olver referenced. I was going to post code but, what with
the difficulties of handling Unicode in Java, and the absence of standard
combinatorial generators in the library, it's a bit more effort to do properly
than it's worth.

-- chris

Should I append 'feasibly' to my list? To use ClassLoader.findClass()
would require checking more than 64K^64K ~ 10^1M combinations to find
every class and probably on the order of 10^22 for more reasonable
assumptions (100 possible characters, 20-character lengths). It would be
much more efficient to open the Jar-files, find the package directory,
and load the classes.