如何在RMI方法中传递参数中的对象？

Question

我试图在RMI方法中添加参数.当我添加例如String一切正常.但我不确定我是否可以传递我创建的对象.我是RMI的新手,所以我的代码非常简单:

HelloIF

public interface HelloIF extends Remote {
    String greeting(Context c) throws RemoteException;
}

你好

public class Hello extends UnicastRemoteObject implements HelloIF {

    public Hello() throws RemoteException {
    }

    public String greeting(Context c) throws RemoteException {
        addToContext(c);
        report(c);
        return "greeting";
    }

    void addToContext(Context c) {
        c.addID(Thread.currentThread().getId());
    }

    void report(Context c) {
        System.out.println("Hello.greeting() thread : "
                + Thread.currentThread().getName() + " "
                + Thread.currentThread().getId());

        System.out.println("Hello.greeting() context : "
                + c.getDistributedThreadName() + " " + c.getRequestType());
    }
}

为RMIServer

public class RMIServer {

    public static void main(String[] args) throws RemoteException, MalformedURLException {
        LocateRegistry.createRegistry(1099);
        HelloIF hello = new Hello();
        Naming.rebind("server.Hello", hello);
        System.out.println("server.RMI Server is ready.");
        System.out.println("RMIServer.main() thread : " + Thread.currentThread().getName() 
                + " " + Thread.currentThread().getId());
    }
}

RMIClient

public class RMIClient {
    public static void main(String[] args) throws RemoteException, MalformedURLException, NotBoundException {

        Context context = new Context("request1", Thread.currentThread().getName()+System.currentTimeMillis());

        Registry registry = LocateRegistry.getRegistry("localhost");
        HelloIF hello = (HelloIF) registry.lookup("server.Hello");
        System.out.println(hello.greeting(context));
        System.out.println("RMIClient.mian() thread : " + Thread.currentThread().getName() 
                + " " + Thread.currentThread().getId());
    }
}

最后我的班级上下文

public class Context 
{
    private String requestType;
    private String distributedThreadName;
    private List<Long> IDList;

   (...) getters/setters
}

我该怎么做才能使传递上下文成为可能？

Answer 1

你的对象应该实现Serializable.我可以看到这将是一个问题.这是必要的,因为两个部分之间的通信是使用序列化完成的,因此需要发送到其他部分的每个对象都需要是类实现的实例Serializable.

public class Context implements Serializable
{
    private String requestType;
    private String distributedThreadName;
    private List<Long> IDList;

   (...) getters/setters
}

请添加serialVersionUID一个好的做法.就像是:

private static final long serialVersionUID = 20120731125400L;