Remote Vs Serializable

Unlike primitive data types, sending an object to a remote JVM is a nontrivial task. A Java object can be simple and self-contained, or it could refer to other Java objects in complex graph-like structure. Because different JVMs do not share heap memory, RMI must send the referenced object and all objects it references. (Passing large object graphs can use a lot of CPU time and network bandwidth.)

Det må betyde at den sender en kopi og hvis ikke så beskriver de det ikke godt nok.

"reference til objektet" = "proxy til objektet"

interessant spoergsmaal - meget interessant spoergsmaal

jeg *tror* at den vil give dig en ArrayList med proxy objekter - jeg synes at
det vil give mest mening

du kan nemt verificere det med et lille test eksempel

jep

ArrayList med procy objekter

her er et eksempel

import java.rmi.Remote;
import java.rmi.RemoteException;
import java.util.ArrayList;

public interface Foobar extends Remote {
    public ArrayList getList() throws RemoteException;
}

import java.rmi.Remote;
import java.rmi.RemoteException;

public interface Data extends Remote {
    public int getA() throws RemoteException;
    public void setA(int a) throws RemoteException;
    public String getB() throws RemoteException;
    public void setB(String b) throws RemoteException;
}

import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;
import java.util.ArrayList;

public class FoobarImpl extends UnicastRemoteObject implements Foobar {
    private ArrayList lst;
    public FoobarImpl(ArrayList lst) throws RemoteException {
        this.lst = lst;
    }
    public ArrayList getList() {
        return lst;
    }
}

import java.rmi.Remote;
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;

public class DataImpl extends UnicastRemoteObject implements Data {
    private int a;
    private String b;
    public DataImpl() throws RemoteException {
        this(0, "");
    }
    public DataImpl(int a, String b) throws RemoteException {
        this.a = a;
        this.b = b;
    }
    public String toString() {
        return "(" + a + "," + b + ")";
    }
    public int getA() {
        return a;
    }
    public void setA(int a) {
        this.a = a;
    }
    public String getB() {
        return b;
    }
    public void setB(String b) {
        this.b = b;
    }
}

import java.net.MalformedURLException;
import java.rmi.Naming;
import java.rmi.NotBoundException;
import java.rmi.RemoteException;

public class Client {
    public static void main(String[] args) {
        try {
            Foobar fb = (Foobar)Naming.lookup("rmi://localhost:9999/Foobar");
            Data d = (Data)fb.getList().get(1);
            d.setA(77);
            d.setB("Test");
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (RemoteException e) {
            e.printStackTrace();
        } catch (NotBoundException e) {
          e.printStackTrace();
        }
    }
}

import java.io.IOException;
import java.net.MalformedURLException;
import java.rmi.Naming;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.util.ArrayList;

public class Server {
    public static void main(String[] args) {
        try {
            ArrayList lst = new ArrayList();
            lst.add(new DataImpl(1, "A"));
            lst.add(new DataImpl(2, "BB"));
            lst.add(new DataImpl(3, "CCC"));
            LocateRegistry.createRegistry(9999);
            Naming.rebind("rmi://localhost:9999/Foobar", new FoobarImpl(lst));
            System.out.println(lst);
            System.out.print("Press enter to continue");
            System.in.read();
            System.out.println(lst);
            System.exit(0);
        } catch (RemoteException e) {
            e.printStackTrace();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Mange tak arne, smider du ikke lige et svar? er nu velfortjente point :)

svar