java - 使用 RMI 的 ClassNotFoundException

Question

我用 RMI 在 netbeans 中编写了一个程序，客户端出现错误

错误:

java.rmi.UnmarshalException: error unmarshalling return; nested exception is: java.lang.ClassNotFoundException: rmiserver.Message (no security manager: RMI class loader disabled) at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)

但是服务器没有任何错误!

接口(interface)代码:

 package rmiclient;

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

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

接口(interface)实现是:

 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:)。

Answer 1

在你的堆栈跟踪中:

java.lang.ClassNotFoundException: rmiserver.Message

但根据您提供的数据，您的Message接口(interface)由包 package rmiclient; 声明并且您还没有创建任何 rmiserver.Message类。

更正包名称。