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:\\class\\");
URL url = file.toURI().toURL();
URL[] urls = new URL[] { url };
ClassLoader loader = new URLClassLoader(urls);
Class cls = loader.loadClass("user.informatin.Class");
}
}