Java RMI 客户端访问被拒绝

Question

我正在编写一个小型 Java RMI 服务器和客户端程序。我花了一些时间试图找出错误消息，但没有成功。

客户端生成以下错误:

Trying to connect to: 127.0.0.1:3232 ERROR!!!: StockClient: main: Could not connect to the server: java.rmi.UnmarshalException: Error unmarshaling return header; nested exception is: java.rmi.UnmarshalException: Error unmarshaling return header; nested exception is: java.io.EOFException java.io.EOFException at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:209) at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:359) at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source) at StockClient.StockClient.main(StockClient.java:44) Caused by: java.io.EOFException at java.io.DataInputStream.readByte(DataInputStream.java:250) at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:195) ... 3 more

只有当客户端尝试连接时，服务器才会出现以下错误。

this address=localhost/127.0.0.1,port=3232 Exception in thread "RMI TCP Connection(idle)" java.security.AccessControlException: access denied (java.net.SocketPermission 127.0.0.1:62586 accept,resolve) at java.security.AccessControlContext.checkPermission(AccessControlContext.java:374) at java.security.AccessController.checkPermission(AccessController.java:549) at java.lang.SecurityManager.checkPermission(SecurityManager.java:532) at java.lang.SecurityManager.checkAccept(SecurityManager.java:1157) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.checkAcceptPermission(TCPTransport.java:636) at sun.rmi.transport.tcp.TCPTransport.checkAcceptPermission(TCPTransport.java:275) at sun.rmi.transport.Transport$1.run(Transport.java:158) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.Transport.serviceCall(Transport.java:155) at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:535) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:790) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:649) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:680)

由于服务器错误，我相当确定它是安全或注册表错误，服务器的安全策略是:

grant { permission java.security.AllPermission; };

并使用以下参数运行

-Djava.security.policy=client.policy

我已经尝试了所有我能找到的方法，但似乎一直在兜圈子。

相关方法:

服务器:

 public static void main(String[] args)
    {//main(...) starts
        // set up the data structures and data

        //add users
        //Users hard coded as this is an example proof on concept program
        //Names and passwords not hashed for simplicity
        User alpha = new User("Alpha", "AlphaPass");
        User omega = new User("Omega", "OmegaPass");
        users.add(alpha);
        users.add(omega);

        //startup the RMI server
        try
        {
            System.setSecurityManager(new RMISecurityManager());
            StockServer server = new StockServer();
            StockServerInterface inter = (StockServerInterface)
UnicastRemoteObject.exportObject (server,0);

            // create the registry and bind the name and object.
            registry = LocateRegistry.createRegistry(thisPort);
            registry.rebind("StockServer", inter);
        }
        catch (Exception e)
        {
            System.out.println("Unable to create StockServer: " + e);
            e.printStackTrace();
            System.exit(1);
        }
    }//main(...) ends


    /**
     * Constructor for StockServer
     *
     * @throws RemoteException
     */
    public StockServer() throws RemoteException
    {

        //try to get the host machine's IP address
        try
        {
            // get the address of this host.
            thisAddress = (InetAddress.getLocalHost()).toString();
        } catch (Exception e)
        {
            throw new RemoteException("can't get inet address. " + e);
        }

        //Set the port
        thisPort = 3232;

        //Print out the server address and port
        System.out.println("this address=" + thisAddress + ",port=" + thisPort);
    }

客户:

private static StockServerInterface stockServer;
static public void main(String args[])
{
    Registry registry;
    //get the server address from the args
    String serverAddress = args[0];

    //get the server port from the args
    String serverPort = args[1];

    //Let the user know we are about to try to connect
    System.out.println("Trying to connect to: " + serverAddress + ":" + serverPort);
    try
    {
        // get the registry
        registry = LocateRegistry.getRegistry(
                serverAddress,
                (new Integer(serverPort)).intValue());
        // look up the remote object
        stockServer = (StockServerInterface) (registry.lookup("StockServer"));


        //Authenticate the user
        authenticate();

        //setup the hashset
        HashSet<Stock> hashStockSet = null;

        //setup the hashset of desired stocks
        try
        {
            hashStockSet = getHashSet();
        } catch (IOException e)
        {
            e.printStackTrace();
            System.exit(1);
        } catch (ClassNotFoundException e)
        {
            e.printStackTrace();
            System.exit(1);
        }
        //bit of a heavy handed infinte loop so we continue to get the loop
        while(true)
        {
            //Run the ticker
            ticker(hashStockSet);
        }

        // call the remote method


    }
    catch (RemoteException e)
    {
        System.out.println("ERROR!!!: StockClient: main: Could not connect to the server: "+e);
        e.printStackTrace();
    }
    catch (NotBoundException e)
    {
        System.out.println("ERROR!!!: StockClient: main: Could not connect to the server: "+e);
        e.printStackTrace();
    }

Answer 1

您不需要在 RMI 服务器中使用 SecurityManager，除非客户端依赖代码库功能为服务器提供类。要么删除它，要么调试 .policy 文件。很明显你写的那个没有被加载。

使用-Djava.security.debug=access,failure 运行您的服务器，您将看到所有安全域从哪里获取它们的配置，以及在抛出异常。