java - RMI 中的 UnsupportedOperationException

Question

我编写了一个简单的程序但是当你通过命令运行客户端时出现此错误

 HelloClient exception:  java.lang.UnsupportedOperationException: Not supported yet.

这是我的编码

接口(interface)类

    import java.rmi.*;

    public interface HelloInterface extends Remote { 

     public String say() throws RemoteException;


   }

实现类

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

         /** 
           *
           * @author x
           */
   public class HelloServerImpl extends UnicastRemoteObject implements HelloInterface {

   private String message; 

   public HelloServerImpl(String msg)throws RemoteException{
   message = msg;
   }


@Override
public String say() throws RemoteException {
    throw new UnsupportedOperationException("Not supported yet.");
}




 }

服务器类

     import java.rmi.Naming;

       /**
        *
        * @author x
        */
       public class HelloServer {
        public static void main (String []args ){
          try {
        Naming.rebind("HELLOSERVER", new HelloServerImpl("Hello word"));
        System.out.println("Hello Server is ready.");
    } catch (Exception ex) {
        System.out.println("Hello server failed: "+ ex);
    }


    }
    }

客户端类

          import java.rmi.Naming;

         /**
          *
          * @author x
          */
             public class HelloClient {
          public static void main(String[]args){

        HelloInterface hello;
        String url = "rmi://localhost/HELLOSERVER";


         try {
        hello = (HelloInterface)Naming.lookup(url);
        System.out.println(hello.say());
    } catch (Exception ex) {
       System.err.println("HelloClient exception:  " + ex);
    }

    }
   }

我准备写步骤了，但还是同样的错误

为什么？

Answer 1

你自己写的:

@Override
public String say() throws RemoteException {
    throw new UnsupportedOperationException("Not supported yet.");
}

当然会抛出异常。尝试实际返回一个字符串:

@Override
public String say() throws RemoteException {
    return "hello";
}