What does this snippet do?

From:

Ramon F Herrera <ramon@conexus.net>

Newsgroups:

comp.lang.java.programmer

Date:

Mon, 3 Dec 2007 21:15:08 -0800 (PST)

Message-ID:

<1334c3c2-dbbe-46b0-8d4a-b4bee53a2982@s19g2000prg.googlegroups.com>

This question would be best answered by somebody with a knowledge of
component based programming methodologies, such as COM, CORBA or the
UNO newcomer; as implemented in Java, of course.

This comes from one of the tutorial examples contained in the
OpenOffice SDK.

I discovered that if I remove the code below, the sample program still
works properly, while being run from inside Eclise or NetBeans. I
removed the code and forgot all about it.

Some time later, I realized that the program didn't run standalone,
from the Unix or Windows shell/CLI, or by double click. So, I put the
chunk of code back, and voila! the program works fine now.

I could try reading the OO developer manual and following the code,
but I am sure some expert out there can give a better explanation.

This whole component based approach looks very intriguing, but somehow
counterintuitive, at least to me.

Thanks for sharing your insight...

-Ramon

-----------------------------------------

ClassLoader loader = ClassLoader.getSystemClassLoader();
if (loader instanceof URLClassLoader) {
     URLClassLoader cl = (URLClassLoader)loader;
     Class sysclass = URLClassLoader.class;
      try {
           Method method = sysclass.getDeclaredMethod("addURL", new
Class[]{URL.class});
           method.setAccessible(true);
           method.invoke(cl, new Object[]{new
File(ooBaseDirectory).toURL()});
           } catch (Throwable t) {
                    t.printStackTrace();
                    throw new IOException("Error, could not add URL to
system classloader");
          }
} else {
          System.out.println("Error occured, URLClassLoader expected
but " +
          loader.getClass() + " received. Could not continue.");
         }