Class Loading on specific diretory

Question

I am writing a plugin based engine and I want to load up my classes(plugins) from a specific directory besides "classes/com/bla/bla/bla"
So, I am using this code:
URL[] url = new URL[1];
try {
url[0] = new URL("file:think/");
catch (MalformedURLException ex) {
URLClassLoader ucl = new URLClassLoader(url);
try {
Class cl = ucl.loadClass(pluginsPackage + "." + "Updater");
System.out.println(cl);
catch (ClassNotFoundException ex1) {
ex1.printStackTrace();
Actually, if I try something like this:
new File("think").list()
will return all my .class files located under that directory.
Another doubt. when I call URLClassLoader.loadClass(string) I must pass the whole class name like "bla.blabla.blabla.myclass" or just "myclass"
Class cl = ucl.loadClass("org.com.info.net.thing.Updater")
(By the way, this ucl.loadClass is giving me the ClassNotFoundException!)
OR
Class cl = ucl.loadClass("Updater")
(By the way, this ucl.loadClass is giving me the NoClassDefFoundError!)
What Am I doing wrong ?
If anybody had an idea, please contact me at msn([email protected]) or reply this topic. thank you!

Answer 1

Actually, if I try something like this:
new File("think").list()
will return all my .class files located under that
directory.
Is there a question here?No! Thats a statement!
I am telling that under my current directory, there is a another one, filled with .class files containing classes implementing some base Interface. That interface will be used to instantiate the object.
Right ?
Apparently you don't have the class you specified in the right place.Well.. Here is the thing...
Even if I set the url using something like this:
url[0] = new File("think").toURL();(You know. this File objet is ok.)
and then:
URLClassLoader ucl = new URLClassLoader(url);
Class cl = ucl.loadClass(pluginsPackage + "." + "Updater");(pluginsPackage + "." + "Updater" = "bla.bla.bla.bla.Updater" )
(just like you guys told me to do. Fully qualified class name)
And then:
java.lang.ClassNotFoundException: br.com.rsl.agent.plugins.think.Updater
     at java.net.URLClassLoader$1.run(URLClassLoader.java:199)
     at java.security.AccessController.doPrivileged(Native Method)
     at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
     at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
     at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
where is the failure ?
:(