Question

我尝试创建一个简单的RMI应用程序，它将两个客户端（Bramka，Monitor）与服务器（Centrala）连接，而client_1（Bramka）与client_2（Monitor）连接

Bramka.class

public class Bramka extends UnicastRemoteObject implements IBramka{

    protected Bramka() throws RemoteException {
        super();
        // TODO Auto-generated constructor stub
    }

    public static void main(String[] args) {
        String url = "//localhost:1099/RMI";
        try{
            ICentrala c = (ICentrala) Naming.lookup(url);
            c.getZarejestrowaneBramki();
        }catch(Exception e){
            System.out.println(e);
        }
    }

    public boolean test() throws RemoteException {
        System.out.print("Something from client1");
    }


}

Centrala.class：

public class Centrala extends UnicastRemoteObject implements ICentrala {


    protected Centrala() throws RemoteException {
        super();
    }

    private static final long serialVersionUID = 1L;

    public static void main(String[] args) {
        String url = "//localhost:1099/RMI";
        try {
            Centrala centrala = new Centrala();
            Naming.rebind(url,centrala);
            System.out.println("centrala wystartowala");
        }catch (Exception e ) {
            System.out.println(e);
        }
    }

    public void getZarejestrowaneBramki() throws RemoteException {
        System.out.println("Something from server");

    }


}

Monitor.class

public class Monitor extends UnicastRemoteObject implements IMonitor{


    protected Monitor() throws RemoteException {
        super();
        // TODO Auto-generated constructor stub
    }

    private static final long serialVersionUID = 1L;

    public static void main(String[] args) {
        String url = "//localhost:1099/RMI";
        try{
            ICentrala c = (ICentrala) Naming.lookup(url);
            IBramka b = (IBramka) Naming.lookup(url); //error
            c.getZarejestrowaneBramki();
            b.test();
        }catch(Exception e){
            System.out.println(e);
        }
    }

    public void koniecznaAktualizacja() throws RemoteException {

    }

}

我想要做的是从test客户端的Bramka客户端运行方法Monitor。如果我尝试这样做，我会得到例外：

java.lang.ClassCastException: com.sun.proxy.$Proxy0 cannot be cast to IBramka

如果我想从Centrala运行方法，它可以正常工作。一些提示？

Answer 1

random.sample(all_perms, k=4)

这没有意义。您正在查找相同的URL两次，并期望能够将其转换为两个不同的远程接口。您需要两个网址，并且您还需要ICentrala c = (ICentrala) Naming.lookup(url); IBramka b = (IBramka)Naming.lookup(url);将自己绑定到第二个网址下的注册表。

另一件没有意义的事是你的术语。这些都是服务器。

客户端之间的Java RMI连接

1 个答案: