Java Class.forName() from distant directory

Question

I am currently loading Java classes using Class.forName() to load it.

clazz = Class.forName("interfaces.MyClass");

But now I want to load classes from different directory, I have tried to set classpath by

clazz = Class.forName("-cp \"C:/dir\" distantinterfaces.DistantClass");

With no success and ClassNotFoundException. Full path to distant class is:

C:/dir/distantinterfaces/DistantClass.class

Answer 1

Use an URLClassLoader for this. The code might be something along the lines of:

File f = new File("C:/dir");
URL[] cp = {f.toURI().toURL()};
URLClassLoader urlcl = new URLClassLoader(cp);
Class clazz = urlcl.loadClass("distantinterfaces.DistantClass");

Answer 2

Either the directory is in the classpath, and you can use Class.forName() (which only accepts fuly qualified name classes, and not -cp command line options), or it's not in the classpath and you should then use a custom class loader.

You're not saying what you really want to do (why are you loading classes dynamically), but your best bet is to have the directory in the classpath.