我用RMI在netbean中编写了一个程序，客户端有错误

错误：

java. rmi.UnmarshalException：错误解组返回；嵌套异常是：java.lang.ClassNotFoundException：rsiver.Message（无安全管理器：禁用RMI类加载器）在sun.rmi.注册。RegistryImpl_Stub.lookup（未知来源）

但sever没有任何错误！

中间电码：

 package rmiclient;

import java.rmi.Remote;
import java.rmi.RemoteException;

public interface Message extends Remote {
    void sayHello(String name) throws RemoteException;
}

接口实现为：

 package rmiserver;

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

public class MessageImpl extends UnicastRemoteObject implements Message {

    public MessageImpl() throws RemoteException {       
    }

    @Override
    public void sayHello(String name) throws RemoteException {
        System.out.println("hello "+name);
    }

}

服务器代码是：

package rmiserver;  
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;

public class Main {

    private void startServer(){
        try {
            // create on port 1099
            Registry registry = LocateRegistry.createRegistry(1099);

            // create a new service named myMessage
            registry.rebind("myMessage", new MessageImpl());
        } catch (Exception e) {
            e.printStackTrace();
        }     
        System.out.println("system is ready");
    }

    public static void main(String[] args) {
        Main main = new Main();
        main.startServer();
    }
}

客户端代码是：

package rmiclient;
import java.rmi.RMISecurityManager;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;

public class Main {

    private void doTest(){

        try {

            // fire to localhost port 1099
            Registry myRegistry = LocateRegistry.getRegistry("127.0.0.1", 1099);


            // search for myMessage service
            Message impl = (Message) myRegistry.lookup("myMessage");

            // call server's method        
            impl.sayHello("edwin");

            System.out.println("Message Sent");
        } catch (Exception e) {
            e.printStackTrace();
        }       
    }

    public static void main(String[] args) {
        Main main = new Main();
        main.doTest();
    }
}

谢谢：）。