problem in start up my RMI server(under ISP) so that it can recieve remote calls over Internet.--Jav
- by Lokesh Kumar
i m creating a Client/Server application in which my server and client can be on the same or on different machines but both are under ISP.
My RMI programs:-
-Remote Intreface:-
//Calculator.java
public interface Calculator
extends java.rmi.Remote {
public long add(long a, long b)
throws java.rmi.RemoteException;
public long sub(long a, long b)
throws java.rmi.RemoteException;
public long mul(long a, long b)
throws java.rmi.RemoteException;
public long div(long a, long b)
throws java.rmi.RemoteException;
}
Remote Interface Implementation:-
//CalculatorImpl.java
public class CalculatorImpl
extends
java.rmi.server.UnicastRemoteObject
implements Calculator {
public CalculatorImpl()
throws java.rmi.RemoteException {
super();
}
public long add(long a, long b)
throws java.rmi.RemoteException {
return a + b;
}
public long sub(long a, long b)
throws java.rmi.RemoteException {
return a - b;
}
public long mul(long a, long b)
throws java.rmi.RemoteException {
return a * b;
}
public long div(long a, long b)
throws java.rmi.RemoteException {
return a / b;
}
}
Server:-
//CalculatorServer.java
import java.rmi.Naming;
import java.rmi.server.RemoteServer;
public class CalculatorServer {
public CalculatorServer()
{
try {
Calculator c = new CalculatorImpl();
Naming.rebind("rmi://"+args[0]+":1099/CalculatorService", c);
} catch (Exception e)
{
System.out.println("Trouble: " + e);
}
}
public static void main(String args[]) {
new CalculatorServer();
}
}
Client:-
//CalculatorClient.java
import java.rmi.Naming;
import java.rmi.RemoteException;
import java.net.MalformedURLException;
import java.rmi.NotBoundException;
public class CalculatorClient {
public static void main(String[] args) {
try {
Calculator c = (Calculator)Naming.lookup("rmi://"+args[0]+"/CalculatorService");
System.out.println( c.sub(4, 3) );
System.out.println( c.add(4, 5) );
System.out.println( c.mul(3, 6) );
System.out.println( c.div(9, 3) );
}
catch (MalformedURLException murle) {
System.out.println();
System.out.println("MalformedURLException");
System.out.println(murle);
}
catch (RemoteException re) {
System.out.println();
System.out.println("RemoteException");
System.out.println(re);
}
catch (NotBoundException nbe) {
System.out.println();
System.out.println("NotBoundException");
System.out.println(nbe);
}
catch (java.lang.ArithmeticException ae) {
System.out.println();
System.out.println("java.lang.ArithmeticException");
System.out.println(ae);
}
}
}
when both Server and client programs are on same machine:-
i start my server program by passing my router static IP address:-192.168.1.35
in args[0] and my server starts...fine.
and by passing the same Static IP address in my Client's args[0] also works fine.
but:-
when both Server and client programs are on different machines:-
now,i m trying to start my Server Program by passing it's public IP address:59.178.198.247 in args[0] so that it can recieve call over internet.
but i am unable to start it.
and the following exception occurs:-
Trouble: java.rmi.ConnectException: Connection refused to host: 59.178.198.247;
nested exception is:
java.net.ConnectException: Connection refused: connect
i think it is due to NAT Problem because i am under ISP.
so,my problem is that how can i start my RMI Server under ISP so that it can recieve remote calls from internet????
