How to use URLClassLoader to load a *.class file?

You must provide the directories or the jar files containing your .class files to the URLClassLoader:

classUrl = new URL("file:///home/kent/eclipsews/SmallExample/bin/");

And yes, you can load as many classes as you like

From the Javadocs for the URLClassLoader(URL[]) constructor:

Constructs a new URLClassLoader for the specified URLs using the default delegation parent ClassLoader. The URLs will be searched in the order specified for classes and resources after first searching in the parent class loader. Any URL that ends with a '/' is assumed to refer to a directory. Otherwise, the URL is assumed to refer to a JAR file which will be downloaded and opened as needed.

So you have two options:

1. Refer to the directory that the .class file is in
2. Put the .class file into a JAR and refer to that

(1) is easier in this case, but (2) can be handy if you're using networked resources.