Loading a Class That Is Not on the Classpath : ClassPath « Reflection « Java Tutorial

1. Java Tutorial
2. Reflection
3. ClassPath

A URLClassLoader can be used to load classes in any directory.

import java.io.File;
import java.net.URL;
import java.net.URLClassLoader;

public class Main {
  public static void main(String[] argv) throws Exception {
    File file = new File("c:\\");

    URL url = file.toURI().toURL(); 
    URL[] urls = new URL[] { url };

    ClassLoader cl = new URLClassLoader(urls);

    Class cls = cl.loadClass("com.mycompany.MyClass");
  }
}