RMI Complicated Issues

Question

This is somewhat of a mess. I am getting an error when my remote object on the server tries to access other objects on the server. I think that what is happening is that the client is instantiating its own object of the remote implementation class, but I really know very little about this. Here's the error (I am really sorry about the assert message; I assumed no one else would read this):

Exception in thread "AWT-EventQueue-0" java.lang.AssertionError: WTF?
at com.eotg.WebInterface.GlobalNetIO.registerAccount(GlobalNetIO.java:123)
at com.eotg.Client.ClientIO.registerAccount(ClientIO.java:92)
at com.eotg.Client.GUI.actionPerformed(GUI.java:260)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

Note that this is on the client side even though GlobalNetIO is a server-side class.

Here's GlobalNetIO:

package com.eotg.WebInterface;

import java.io.Serializable;
import java.rmi.RemoteException;
import java.util.ArrayList;

import com.eotg.Engine.Galaxy;
import com.eotg.UserSystem.User;
import com.eotg.Util.MathC;
import com.eotg.WebUtils.*;

public class GlobalNetIO implements EotGRemote, Serializable
{
    /**
     * 
     */
    private static final long serialVersionUID = 4316258945377312760L;
    public static final String DIR = "c:/Users/Josh/Dropbox/EotG/Eo_Nova_Server/";
    ArrayList<UserNetIO> m_UserInterfaces;

    public GlobalNetIO()
    {
        m_UserInterfaces = new ArrayList<UserNetIO>();
    }

    protected void handleNewClient()
    {

    }

    public static void ErrorMessage(boolean b, String sz)
    {
        if (b)
        {
            System.err.print(sz);
        }
    }

    public ArrayList<UserNetIO> getUserInterfaces()
    {
        return m_UserInterfaces;
    }

    public int getNumUserInterfaces()
    {
        return m_UserInterfaces.size();
    }

    public UserNetIO getUserInterface(int i)
    {
        assert i > -1 : "Invalid index.";
        assert i < getNumUserInterfaces() : "Invalid index.";
        return m_UserInterfaces.get(i);
    }

    public UserNetIO getUserInterface(String szID)
    {
        for (int i = 0; i < getNumUserInterfaces(); i++)
        {
            if (getUserInterface(i).getIDString().equals(szID))
                return getUserInterface(i);
        }
        return null;
    }

    private String makeIDString(int iNumChars)
    {
        char[] str = new char[iNumChars];
        for (int i = 0; i < iNumChars; i++)
        {
            str[i] = MathC.randomValidChar();
        }
        String sz = String.valueOf(str);
        for (int i = 0; i < getNumUserInterfaces(); i++)
        {
            if (sz.equals(getUserInterface(i).getIDString()))
            {
                sz = makeIDString(iNumChars);
            }
        }
        return sz;
    }

    @Override
    public String[] login(String szUsername, String szPassword) throws RemoteException 
    {
        String[] szPhrases;
        User u = Galaxy.World.getUserByName(szUsername);
        if (u == null)
        {
            szPhrases = new String[]{"0","Username is not valid."};
            return szPhrases;
        }

        if (!u.getPassword().equals(szPassword))
        {
            szPhrases = new String[]{"0","Username is valid but password is incorrect."};
            return szPhrases;
        }
        String sz = makeIDString(32);
        UserNetIO UsrIO = new UserNetIO(sz,u);
        getUserInterfaces().add(UsrIO);
        return new String[]{sz};
    }

    @Override
    public void logout(String szID) throws RemoteException 
    {
        for (int i = 0; i < getNumUserInterfaces(); i++)
        {
            if (getUserInterface(i).getIDString().equals(szID))
            {
                getUserInterfaces().remove(i);
                return;
            }
        }
    }

    @Override
    public String[] registerAccount(String szUsername, String szFirstName, String szLastName, String szEmail) throws RemoteException 
    {
        String[] szPhrases;
        assert Galaxy.World != null : "WTF?";
        if (Galaxy.World.getUserByName(szUsername) != null)
        {
            szPhrases = new String[]{"0","Register failed: That username is already in use."};
            return szPhrases;
        }
        if (Galaxy.World.getUserByEmail(szEmail) != null)
        {
            szPhrases = new String[]{"0","Register failed: An account is already registered with that email."};
            return szPhrases;
        }

        Galaxy.World.addUser(szUsername, szFirstName, szLastName, szEmail);
        szPhrases = new String[]{"1", "Register success! Your password is:" + Galaxy.World.getUser(Galaxy.World.getNumUsers()-1).getPassword()};
        return szPhrases;
    }

    @Override
    public String[] getUserAttribute(String szID, int iAttribute) throws RemoteException 
    {
        return getUserInterface(szID).getUserAttribute(iAttribute);
    }

    @Override
    public String[] tryChangeUserAttribute(String szID, int iAttribute, String szNewVal)
    {
        return getUserInterface(szID).tryChangeUserAttribute(iAttribute, szNewVal);
    }

    @Override
    public int getNumRaceInfos() throws RemoteException 
    {
        return Galaxy.World.getNumRaceInfos();
    }

    @Override
    public int getNumFactionInfos() throws RemoteException 
    {
        return Galaxy.World.getNumFactionInfos();
    }
}

Some relevant bits of Galaxy (Server-side):

package com.eotg.Engine;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.rmi.RMISecurityManager;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.util.ArrayList;
import java.util.List;

import JeXML.InfoBase;
import JeXML.JeTextMgr;
import JeXML.JeXMLInterface;

import com.eotg.AI.God;
import com.eotg.ConstantInfos.Element;
import com.eotg.ConstantInfos.FactionInfo;
import com.eotg.ConstantInfos.Molecule;
import com.eotg.ConstantInfos.PlanetType;
import com.eotg.ConstantInfos.PrefabSystem;
import com.eotg.ConstantInfos.RaceInfo;
import com.eotg.ConstantInfos.StarType;
import com.eotg.Game.GameObject;
import com.eotg.Game.Biology.Organism;
import com.eotg.UserSystem.DateTime;
import com.eotg.UserSystem.Player;
import com.eotg.UserSystem.User;
import com.eotg.Util.Point;
import com.eotg.WebInterface.GlobalNetIO;
import com.eotg.WebUtils.WebConstants;
public class Galaxy 
{
    //Basic Galaxy Stuff
    public static Galaxy World;
//...
public God GOD;
//...
protected GlobalNetIO IO;
//...
protected void makeRMI(GlobalNetIO bondee)
    {
        System.setProperty("java.security.policy",GlobalNetIO.DIR+"bin/settings.policy");
        //System.setProperty("java.rmi.server.codebase", "file:/"+GlobalNetIO.DIR+"bin/");

        if (System.getSecurityManager() == null)
            System.setSecurityManager ( new RMISecurityManager() );
        try
        {
            Registry reg = LocateRegistry.createRegistry(WebConstants.PORT);
            reg.bind(WebConstants.SERVICE_NAME, bondee);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }
//...
protected void makeRMI(GlobalNetIO bondee)
    {
        System.setProperty("java.security.policy",GlobalNetIO.DIR+"bin/settings.policy");
        //System.setProperty("java.rmi.server.codebase", "file:/"+GlobalNetIO.DIR+"bin/");

        if (System.getSecurityManager() == null)
            System.setSecurityManager ( new RMISecurityManager() );
        try
        {
            Registry reg = LocateRegistry.createRegistry(WebConstants.PORT);
            reg.bind(WebConstants.SERVICE_NAME, bondee);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }

ClientIO:

package com.eotg.Client;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.rmi.NotBoundException;
import java.rmi.RMISecurityManager;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import com.eotg.WebUtils.*;

public class ClientIO
{
    protected EotGRemote m_RemoteStream;
    protected String m_szClientID;
    public static String URL = "192.168.1.4";
    public static final String DIR = "c:/Users/Josh/Dropbox/EotG/";

    public ClientIO()
    {
        System.setProperty("java.rmi.server.codebase", "file:/"+DIR+"/Eo_Nova_Server/bin/");
        System.setProperty("java.security.policy", DIR+"/Eo_Nova_Client/bin/settings.policy");
        if (System.getSecurityManager() == null)
        {
            System.setSecurityManager(new RMISecurityManager());
        }
        System.out.println("Enter the Server IP adress (The IP adress of the machine that the server is running on)");
        try 
        {
            ClientIO.URL = new BufferedReader(new InputStreamReader(System.in)).readLine();
        }
        catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        /*try {
            URL = java.net.InetAddress.getLocalHost().getHostName();
        } catch (UnknownHostException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }*/
        Connect();
    }

    public EotGRemote getRemoteStream()
    {
        return m_RemoteStream;
    }

    public String getClientID()
    {
        return m_szClientID;
    }

    public String getServerMessage()
    {
        try 
        {
            Registry registry = LocateRegistry.getRegistry(URL, WebConstants.PORT);
            //different physical machines, this might have to change
            m_RemoteStream = (EotGRemote) registry.lookup(WebConstants.SERVICE_NAME);
        }
        catch (RemoteException | NotBoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return "";
    }
//...
public void registerAccount(String szUsername, String szFirstName, String szLastName, String szEmail)
    {
        try{
            String[] psz = getRemoteStream().registerAccount(szUsername, szFirstName, szLastName, szEmail);
        boolean bSuccess = psz[0].equals("1");
        if (bSuccess)
            GUI.Global.destroyRegisterBox();
        }
        catch (RemoteException e)
        {
            e.printStackTrace();
        }
    }

The EotGRemote interface, which extends remote and is implemented by GlobalNetIO.

package com.eotg.WebUtils;

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

public interface EotGRemote extends Remote 
{
    //Basic methods
    public void logout(String szID) throws RemoteException;

    //User-specific methods
    public String[] login(String szUsername, String szPassword) throws RemoteException;
    public String[] getUserAttribute(String szID, int iAttribute) throws RemoteException;
    public String[] tryChangeUserAttribute(String szID, int iAttribute, String szNewVal) throws RemoteException;

    //Global Context Methods
    public int getNumRaceInfos() throws RemoteException;
    public int getNumFactionInfos() throws RemoteException;
    public String[] registerAccount(String szUsername, String szFirstName, String szLastName, String szEmail) throws RemoteException;

}

Am I right? And regardless, can anyone point me towards fixing this error?

Answer 1

public class GlobalNetIO implements EotGRemote, Serializable

Make that

public class GlobalNetIO extends UnicastRemoteObject implements EotGRemote

throwing Serializable away, and add throws RemoteException to its constructor.

At present GlobalNetIO isn't a remote object at all, it is what I would call a mobile agent. It is serialized to the Registry, and again to the client when it does the lookup, and executes there.