RMI

package Service;
import java.rmi.*;
 
interface Service extends Remote {
 
    public void newCard(String card) throws RemoteException;
 
    public void addMoney (String card, double money) throws RemoteException;
 
    public void subMoney (String card, double money) throws RemoteException;
 
    public Double getBalance (String card) throws RemoteException;
}
 
package Service;
import java.util.HashMap;
import java.rmi.*;
import java.rmi.server.*;
 
public class ServiceImpl extends UnicastRemoteObject implements Service{
    HashMap hash = new HashMap();
    public ServiceImpl() throws RemoteException{}
 
    public void newCard(String card){
        hash.put(card, new Double (0.0));
    }
    public void addMoney(String card, double money) throws RemoteException{
        Double d = (Double) hash.get(card);
        if (d != null) hash.put(card,new Double( d + money));
        else throw new ConnectException();
    }
    public void subMoney(String card, double money)throws RemoteException{
        Double d = (Double) hash.get(card);
        if (d != null) hash.put(card,new Double( d - money));
        else throw new ConnectException();
    }
    public Double getBalance(String card) throws RemoteException{
        Double d = (Double) hash.get(card);
        if(d!=null) return d;
        else throw new ConnectException();
    }
    public static void main(String [] args)throws Exception{
        Service serv = new ServiceImpl();
        String local = "rmi://localhost/Service";
        Naming.rebind(local, serv);
    }
}
 
package Service;
import java.rmi.*;
 
public class ConnectException extends RemoteException{
}
 
package Service;
import java.rmi.*;
 
class Client {
    static String y;
    public static void main(String[] args) throws Exception {
        String local = "rmi://localhost/Service";
        Service serv = (Service) Naming.lookup(local);
 
        for(Integer r = 5; r<=0; r++){
            try{
                y = r.toString();
                Double t = r.doubleValue();
                serv.addMoney(y, t);
            }catch(RemoteException e){
                serv.newCard(y);
            }
        }
        for(Integer g = 5; g<=0; g++){
            String r = g.toString();
            System.out.println("Баланс ровняется" + serv.getBalance(r));
        }
    }