RMI的问题.

做了一个简单的RMI例子,但是一直有问题, 接口:

 
package rmi;
import java.rmi.Remote;
import java.rmi.RemoteException;
public interface MyRemote extends Remote {
	
	public String sayHello() throws RemoteException;
	
}

实现类

 
package rmi;

import java.rmi.Naming;
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;

public class MyRemoteImp extends UnicastRemoteObject implements MyRemote {

	protected MyRemoteImp() throws RemoteException {

	}

	public String sayHello() throws RemoteException {
		// TODO 自动生成方法存根
		return "Server says,'hey'";
	}

	public static void main(String[] args) {
		try {
			// 产生远程对象
			MyRemote service = new MyRemoteImp();
			// 注册服务
			Naming.rebind("RemoteHello", service);
			System.out.println("++++++++++++++");
		} catch (Exception e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();

		}

	}

}

客户端类:

 
package rmi;

import java.net.MalformedURLException;
import java.rmi.*;

public class MyRemoteClient {
	public static void main(String args[]) {
		new MyRemoteClient().go();
	}

	public void go() {
		try {
			 MyRemote service=(MyRemote)Naming.lookup("rmi:192.168.0.107//RemoteHello");
			 String s=service.sayHello();
			 System.out.println(s);

		} catch (MalformedURLException e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();
		} catch (RemoteException e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();
		} catch (NotBoundException e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();
		}
	}
}

在DOS窗口编译成功后执行:
rmic rmi.MyRemoteImp(生成stub文件)
start rmiregistry (打开注册服务)
java rmi.MyRemoteImp(注册)
都顺利执行

打开另一DOS窗口:
执行:java rmi.MyRemoteClient 出现下面错误
Exception in thread "main" java.lang.ClassCastException: sun.rmi.registry.RegistryImpl_Stub
at rmi.MyRemoteClient.go(MyRemoteClient.java:19)
at rmi.MyRemoteClient.main(MyRemoteClient.java:8)

根据提示找到这行:
MyRemote service=(MyRemote)Naming.lookup("rmi:192.168.0.107//RemoteHello");

出现了ClassCastException异常.
Naming.lookup返回的是Remote类.

why????
在网上看了很多贴子,也有人发生一样样的问题,但是没有找到解决办法,大家有没有思路啊?