Running a java Custom ClassLoader program in STS is giving issue

[Maan Suraj]

I thought of creating a Custom ClassLoader to know how it works. I went to this site Custom Class Loader and copied the code to my STS.

When i try running from my command prompt, i get the desired output like below.As the site says, I only compiled "CCLRun.java" and "CompilingClassLoader.java". I leave rest of the files to be compiled by my Custom Class Loader.

now i do below
% java CCLRun Foo arg1 arg2

and i get the desired ouptut like below

CCL: Compiling Foo.java...
foo! arg1 arg2
bar! arg1 arg2
baz! arg1 arg2
CCL: Compiling Boo.java...
Boo!

Now i thought i will try the same in my STS, so that i can debug it and see the execution of the code.

What i did was rt click on the project-->Debug as-->Debug Configurations-->Arguments.

In arguments i give name as CCLRun and program arguments as Foo arg1 arg2.

But when i try above i get below exception

Exception in thread "main" java.lang.ClassNotFoundException: Foo
	at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
	at java.lang.ClassLoader.findSystemClass(ClassLoader.java:916)
	at CompilingClassLoader.loadClass(CompilingClassLoader.java:103)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
	at CCLRun.main(CCLRun.java:20)

What can the problem be?