java - RMI:ServerException、RemoteException、UnmarshalException、UnmarshalException

Question

我遵循了本教程:https://docs.oracle.com/javase/6/docs/technotes/guides/rmi/hello/hello-world.html#5

我在命令提示符下编译了它们，然后启动了 rmiregistry。然后，在我输入后:

    start java -classpath "." example.Server

它没有显示“服务器就绪”。但是，它也没有显示任何错误。

当我在 Eclipse 上尝试时，它显示了以下内容:

  Server exception: java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: 
java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
java.lang.ClassNotFoundException: example.Hello
    java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: 
java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
java.lang.ClassNotFoundException: example.Hello

Hello.java

   package example;

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

   public interface Hello extends Remote
   {
        String sayHello() throws RemoteException;
   }

服务器.java

    package example;

    import java.rmi.registry.Registry;
    import java.rmi.registry.LocateRegistry;
    import java.rmi.RemoteException;
    import java.rmi.server.UnicastRemoteObject;

     public class Server implements Hello
    {

           public Server() {}

           public String sayHello()
           {
           return "Hello, world!";
           }

public static void main(String args[]) {

    try {
        Server obj = new Server();
        Hello stub = (Hello) UnicastRemoteObject.exportObject(obj, 0);

        // Bind the remote object's stub in the registry
        Registry registry = LocateRegistry.getRegistry();
        registry.bind("Hello", stub);

        System.err.println("Server ready");
    } catch (Exception e) {
        System.err.println("Server exception: " + e.toString());
        e.printStackTrace();
    }
}

}

客户端.java

   package example;

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

   public class Client 
   {

        private Client() {}

       public static void main(String[] args) 
       {

            String host = (args.length < 1) ? null : args[0];
            try {
                  Registry registry = LocateRegistry.getRegistry(host);
                  Hello stub = (Hello) registry.lookup("Hello");
                  String response = stub.sayHello();
                  System.out.println("response: " + response);
            } catch (Exception e) {
            System.err.println("Client exception: " + e.toString());
            e.printStackTrace();
            }
      }
   }

我是否遗漏了任何步骤？我该怎么办？

Answer 1

ClassNotFoundException: example.Hello - 您的应用程序找不到此类。将此类添加到客户端和服务器的类路径中。

如果您在 Sserver 之外的其他 PC 上启动客户端，请不要忘记将您的类 example.Hello 与您的客户端一起复制。