Re: Changing classpath at runtime

[Per Bothner <per at bothner dot com>]

On 05/28/2011 11:46 AM, Helmut Eller wrote:
> Is it possible to change the classpath at runtime?
>
> I'd like to do something like
>
> (add-to-classpath ".../foo.jar")
>
> <... use classes in foo.jar ...>
>
> Is Kawa's prepared for that or is the classpath de facto immutable?

First you need to create a "delegating" ClassLoader.  This manages a
dynamic search path of sub-ClassLoaders or just jar files directly.  A 
request to
the delegating ClassLoader is forwarded to the sub-ClassLoaders or the
jar files.

Then you need to make sure class loading uses this delegating ClassLoader.
I assume you can use java.lang.Thread#setContextClassLoader.  I'm not 
familiar
with how to do this in practice.  It's possible you might need to start 
a fresh
thread.

There is probably example code and articles available on the internet,
but I don't haven't anything to point you at.
--
	--Per Bothner
per@bothner.com   http://per.bothner.com/