设计自己的类加载器

import java.io.FileInputStream;
import java.io.IOException;
import java.lang.reflect.Method;

class MyClassLoader extends ClassLoader {
  public Class findClass(String name) {
    byte[] classData = null;
    try {
      FileInputStream f = new FileInputStream("C:\\" + name + ".class");
      int num = f.available();
      classData = new byte[num];
      f.read(classData);
    } catch (IOException e) {
      System.out.println(e);
    }
    Class x = defineClass(name, classData, 0, classData.length);
    return x;
  }
}

public class MainClass {

  static public void main(String args[]) throws Exception {
    MyClassLoader x = new MyClassLoader();
    Class c = x.loadClass(args[0]);
    Class getArg1[] = { (new String[1]).getClass() };
    Method m = c.getMethod("main", getArg1);
    String[] my1 = { "arg1 passed", "arg2 passed" };
    Object myarg1[] = { my1 };
    m.invoke(null, myarg1);
  }
}