自定义ClassLoader问题

今天看了ClassLoader基本原理，想自定义个ClassLoader加载类，对任何路径的class类都实用，代码如下：

package test;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

import org.apache.commons.io.FileUtils;

public class MyClassLoader extends ClassLoader {

@Override
protected Class<?> findClass(String name) throws ClassNotFoundException {
    String path = null;
    String[] names = null;
    try {
        path = super.getSystemResource("").getPath();
        names = name.split("/");
        FileUtils.copyFile(new File(name), new File(path+"/"+(getPkgname()+"\\.").replaceAll("\\.", "/")+names[names.length-1]));
    } catch (IOException e) {
        e.printStackTrace();
    }
    String classname = getPkgname()+"."+names[names.length-1].split("\\.")[0];
    return super.getSystemClassLoader().loadClass(classname);
}

private String pkgname;
public String getPkgname() {
    return pkgname;
}
public void setPkgname(String pkgname) {
    this.pkgname = pkgname;
}

}

 public static void main(String[] args) throws SQLException {
        try {
            MyClassLoader my = new MyClassLoader();
            my.setPkgname("test");
            Class c = my.findClass("D:/Test2.class");
            Object o = c.newInstance();
            Method[] methods = c.getDeclaredMethods();
            for (int i = 0; i < methods.length; i++) {
                System.out.println(methods[i].getName());
                methods[i].invoke(o, null);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } 

package test;

public class Test2 {

public void printa(){
    System.out.println("xixi");
}

}

以上分别为自定义类，测试运行类和被加载类。
代码很简单，现在问题是类似这种加载classpath外的绝对路径的类java本身的ClassLoader没有这样的方法吗？然后我这样自定义的Classloader怎么在加载时启动？不可能想上面这样直接调用加载器的方法吧，求csdn大神指点！

http://a123159521.iteye.com/blog/1095264