JAVA RMI获取传递ArrayList元素

我有一个服务器，它在“ServerInfo”中包含一个ArrayList，当我试图从ClientRMI中获取ArrayList（在ServerInfo中）的一个元素时，例如adf.getSGM（0）.incrementCount（）

“count”并没有增加，就好像每次我调用它时，它都会实例化一个新类SGM

简单地说，我想从ClientRMI与ServerInfo上的ArrayList进行交互（对不起，用英语）

课程包括：

服务器

客户

public class ClientRMI {

    private ServerInfoInterface sgmInterface;
    public  void startServer() {
        String name = "ServerInfo";
        Registry registry;



        try {
            registry = LocateRegistry.getRegistry(9000);

            try {
                sgmInterface = (ServerInfoInterface) registry.lookup(name);

                sgmInterface.getSGM(0).incrementCount();
                System.out.println(sgmInterface.getSGM(0).getCount());  // always 0


            } catch (AccessException e) {
                System.out.println("RIM AccessException"+ e.toString());
            } catch (RemoteException e) {
                System.out.println("RIM RemoteException"+ e.toString());
            } catch (NotBoundException e) {
                System.out.println("RIM NotBoundException"+ e.toString());
            }

        } catch (RemoteException e) {
            System.out.println("RIM RemoteException registry"+ e.toString());
        }

    }

}

---

您正在服务器上创建一个SGM，通过序列化将其传递给客户端，在客户端增加其计数，然后期望该计数在服务器上神奇地增加

它不能工作

您必须使SGM成为一个远程对象，具有自己的远程接口，或者在原始远程接口中提供一个远程方法，以增加由索引指定的GSM计数

public class ServerInfo implements ServerInfoInterface{
    private ArrayList<SGM>  sgmHandler                  = new ArrayList<SGM>();

    // Singleton pattern
    private static ServerInfo instance;

    // Singleton pattern

    public static ServerInfo getInstance() {
        if (instance == null){
            System.out.println("ServerInfo new instance");
            instance = new ServerInfo();
            }
        return instance;
    }

    @Override
    public synchronized void addSGM(SGM sgm) throws RemoteException {
        sgmHandler.add(sgm);

    }

    @Override
    public synchronized SGM getSGM(int i) throws RemoteException {
        return sgmHandler.get(i);

    }

}

public interface ServerInfoInterface extends Remote{

    public void addSGM(SGM sgm) throws RemoteException;
    public SGM getSGM(int i) throws RemoteException;

}

public class SGM implements Serializable{
    /**
     * 
     */
    private static final long serialVersionUID = -4756606091542270097L;
    private int count=0;

    public void incrementCount(){
        count++;
    }

    public void decrementCount(){
        count--;
    }

    public int getCount(){
        return count;
    }

}

public class ClientRMI {

    private ServerInfoInterface sgmInterface;
    public  void startServer() {
        String name = "ServerInfo";
        Registry registry;



        try {
            registry = LocateRegistry.getRegistry(9000);

            try {
                sgmInterface = (ServerInfoInterface) registry.lookup(name);

                sgmInterface.getSGM(0).incrementCount();
                System.out.println(sgmInterface.getSGM(0).getCount());  // always 0


            } catch (AccessException e) {
                System.out.println("RIM AccessException"+ e.toString());
            } catch (RemoteException e) {
                System.out.println("RIM RemoteException"+ e.toString());
            } catch (NotBoundException e) {
                System.out.println("RIM NotBoundException"+ e.toString());
            }

        } catch (RemoteException e) {
            System.out.println("RIM RemoteException registry"+ e.toString());
        }

    }

}