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我是意大利人，很抱歉我的英语不好。

我正在用 Java 编写一个 RMI 程序，这是连接到 RMI 服务器的节点代码部分：

try
        {//trying to connect to the Server
        Remote RemoteObject;
        BootstrapServer_Interface serverObject;
        Registry r = LocateRegistry.getRegistry(10001);
        RemoteObject = r.lookup("BOOTSTRAP-SERVER");//THIS IS LINE 52
        serverObject = (BootstrapServer_Interface)RemoteObject;
        //I get an ip as Server's answerw
        System.out.println("Il nodo "+Thread.currentThread()+" si mette in attesa");
        String ipBN = serverObject.start_join_node(fakeip);
        if(ipBN.equals("-1"))
            {System.out.println("Creazione del nodo "+Thread.currentThread()+" fallito");
            return;
            }

但是，有时，程序会出现以下异常：

java.rmi.ConnectIOException: Exception creating connection to: 131.114.43.246; nested exception is: 
    java.net.SocketException: Socket operation on nonsocket: connect
    at sun.rmi.transport.tcp.TCPEndpoint.newSocket(Unknown Source)
    at sun.rmi.transport.tcp.TCPChannel.createConnection(Unknown Source)
    at sun.rmi.transport.tcp.TCPChannel.newConnection(Unknown Source)
    at sun.rmi.server.UnicastRef.newCall(Unknown Source)
    at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
    at StorageNode.run(StorageNode.java:52)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.net.SocketException: Socket operation on nonsocket: connect
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.PlainSocketImpl.doConnect(Unknown Source)
    at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.<init>(Unknown Source)
    at java.net.Socket.<init>(Unknown Source)
    at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(Unknown Source)
    at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(Unknown Source)
    ... 9 more

这是客户端连接到 RMI 服务器的代码：

try
            {//scelgo casualmente un dato da cercare        
            //genero il mio indirizzo ip
            fakeip = String.valueOf((int) (Math.random() * 256)) + "."
                    + String.valueOf((int) (Math.random() * 256)) + "."
                    + String.valueOf((int) (Math.random() * 256)) + "."
                    + String.valueOf((int) (Math.random() * 256));
            //creo una Socket UDP con cui contattare il Nodo di Bootstrap
            UDPServiceSocket = scanner.UDPSocket();
            if(UDPServiceSocket==null)
                {System.out.println("Tentativo di creazione socket UDP fallito...");
                *return;}
            int UDPport = UDPServiceSocket.getLocalPort();
            fakeip=fakeip+" UDPport="+UDPport;
            //mi connetto al server tramite RMI
            Remote RemoteObject;
            Registry r = LocateRegistry.getRegistry(10001);
            RemoteObject = r.lookup("BOOTSTRAP-SERVER");//THIS IS LINE 48
            serverObject = (BootstrapServer_Interface)RemoteObject;
            //Ottengo l'ip del Bootstrap Node a cui connettermi
            System.out.println("Il client "+Thread.currentThread()+" si mette in attesa.");         
            ipBN = serverObject.client_search();
            }

以及这种情况下的异常（不一定与我上面发布的节点异常一起发生）

java.rmi.ConnectIOException: Exception creating connection to: 131.114.43.246; nested exception is: 
    java.net.SocketException: Socket operation on nonsocket: connect
    at sun.rmi.transport.tcp.TCPEndpoint.newSocket(Unknown Source)
    at sun.rmi.transport.tcp.TCPChannel.createConnection(Unknown Source)
    at sun.rmi.transport.tcp.TCPChannel.newConnection(Unknown Source)
    at sun.rmi.server.UnicastRef.newCall(Unknown Source)
    at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
    at Client.run(Client.java:48)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.net.SocketException: Socket operation on nonsocket: connect
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.PlainSocketImpl.doConnect(Unknown Source)
    at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.<init>(Unknown Source)
    at java.net.Socket.<init>(Unknown Source)
    at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(Unknown Source)
    at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(Unknown Source)

我找不到导致此异常的任何原因。

我很抱歉我之前发布的代码较少，但它只是一个大项目的一小部分，所以我无法通过所有代码：D

但是，如果您需要它，我可以给您一些有关它的信息：

  1. 这是一个 DHT 项目，这是他尝试联系 Bootstrap 服务器（实际上是 RMI 服务器）时的节点代码。

  2. RMI 服务器方法可以被许多节点（上面的代码）和/或许多客户端同时调用。

  3. 创建节点和/或客户端调用的服务器方法来管理安装在服务器上的监视器。
  4. 通过这个监视器，节点和客户端按照“写者和读者”的模型（互斥 ecc.）修改一个 Hash Table。

非常感谢所有帮助我解决这个问题的人，再次为我的英语不好感到抱歉！

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