Java 动态加载类问题

项目 DD 如下描述:
有一个接口类   A.
有个动态载入指定类  B.
动态载入类 B 是通过传递一个参数classPath='com.xxx.test.aImpl' 来进行动态加载指定类.

DD 发布运行正常.
当将 DD 打包成jar放在 EE 项目下用的时候,出现:
java.io.FileNotFoundException
java.lang.ClassNotFoundException

EE 项目中有 A 接口实现类.调用 B 的动态加载.出现找不到接口 A .

不打包执行正常,打包后就出现错误.

/**
 * 自定义的类加载器
 */
public class DynaLoadClass extends ClassLoader {
	private static String PATH = null;
	
	@SuppressWarnings("unchecked")
	protected Class findClass(String name) throws ClassNotFoundException {
		try {
			String classPath = getClassPath(name);
			FileInputStream fin = new FileInputStream(classPath);
			File cf = new File(classPath);
			byte[] raw = new byte[(int) cf.length()];
			fin.read(raw);
			fin.close();
			return defineClass(name, raw, 0, raw.length);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return super.findClass(name);
	}
	/**
	 * 得到Class的绝对路径
	 * @param name
	 * @return
	 */
	private String getClassPath(String name) {
		if(PATH == null){
			PATH = DynaLoadClass.class.getClassLoader().getResource("").toString()
			.replace("file:/", "").replace("%20", " ");
		}
		return PATH + name.replace('.', File.separatorChar) + ".class";
	}
}

该怎么解决啊.求救!
---16:23---
问题解决.
当查找接口的时候,就直接去jar包中找.

@SuppressWarnings("unchecked")
	protected Class findClass(String name) throws ClassNotFoundException {
		try {
			if(name.equals("com.xxxx.gui.IGui")){
				return getIGuiPath();
			}
			String classPath = getClassPath(name);
			FileInputStream fin = new FileInputStream(classPath);
			File cf = new File(classPath);
			byte[] raw = new byte[(int) cf.length()];
			fin.read(raw);
			fin.close();
			return defineClass(name, raw, 0, raw.length);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return super.findClass(name);
	}

	/**
	 * 得到Class的绝对路径
	 * 
	 * @param name
	 * @return
	 */
	private String getClassPath(String name) {
		if (PATH == null) {
			PATH = DynaLoadClass.class.getClassLoader().getResource("")
					.toString().replace("file:/", "").replace("%20", " ");
		}
		return PATH + name.replace('.', File.separatorChar) + ".class";
	}

	@SuppressWarnings("unchecked")
	private Class getIGuiPath() throws ClassNotFoundException, MalformedURLException {
		String path = DynaLoadClass.class.getClassLoader().getResource("").toString().replace("WEB-INF/classes/", "WEB-INF/lib/xxxxxx.jar");
		URL url = new URL(path);
		URLClassLoader loader = new URLClassLoader(new URL[] { url });
		return loader.loadClass("com.xxxx.gui.IGui");
	}