Re: Declaring Java classes and methods -- JAVA400-L

David,

this depends on implementation doesnt it.

By using the superclasses implementation of loadClass, which is
URLClassloader, wont my custom classloader only load classes that havent
already been loaded by a parent?

cheers
Colin.W


----- Original Message ----- 
From: "David Morris" <David.Morris@xxxxxxxxxxxxx>
To: <java400-l@xxxxxxxxxxxx>
Sent: Monday, August 30, 2004 8:59 PM
Subject: Re: Declaring Java classes and methods


> Colin,
>
> Be aware that custom class loaders are generally not expected
> particularly in container-managed environments. You can run into all
> kinds of difficult to debug situations when you load the same class from
> multiple class loaders. It may work for you but I wouldn't use a
> customer class loader to save typing on my classpath. Some reasons to
> use a custom class loader are that you have something in your classes
> you don't want anyone to find out about or you want to be able to reload
> a class at will. A safe but effective alternative to add all Jars in a
> directory is a shell script using something like:
>
> #! /bin/qsh
>
> cd $(dirname $0)
>
> CLASSPATH=.
> for i in lib/*.jar; do
>   CLASSPATH=${CLASSPATH}:$i
> done
>
> echo CLASSPATH=${CLASSPATH}
> export -s CLASSPATH=${CLASSPATH}
>
> java com.MyApp...
>
> --David Morris
>
> >>> colin.williams@xxxxxxxxxxxx 8/30/2004 1:25:59 PM >>>
> Joe,
>
> if you need to write a custom classloader, there are some articles on
> the
> IBM developerworks site that discuss this(assuming you havent done
> this
> before!).
>
> I recently knocked up a custom classloader so that i could setup my
> classpath dynamically, rather than setting using the RUNJVA command.
>
> I had an application that used a component dependent on a lot of open
> source
> JARS, and I didnt want to type them all in to the classpath one by
> one.
> So I created custom classloader that I could point at a directory, and
> it
> would add all the jars to the classpath.
>
> cheers
> Colin.W
> --
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