Im a little stuck with RMI please help

Question

Ok from the beginning
Im running jdk1.5.0_09 its located in C:\Program FIles\Java
The files are held in C:\java
I have created a simple calculator program Code below:
Calculator.java
Calculator.class
(code)
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;
} (/code)
CalculatorImpl.java
CalculatorImpl.class
(code)
public class CalculatorImpl
extends
java.rmi.server.UnicastRemoteObject
implements Calculator{
// Implementations must have an
//explicit constructor
// in order to declare the
//RemoteException exception
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;
(/code)
calculatorserver.java
calculatorserver.class
(code)
import java.rmi.Naming;
public class CalculatorServer {
public CalculatorServer() {
try {
Calculator c = new CalculatorImpl();
Naming.rebind("rmi://localhost:1099/CalculatorService", c);
} catch (Exception e) {
System.out.println("Trouble: " + e);
public static void main(String args[]) {
new CalculatorServer();
(/code)
calculatorclient.java
calculatorclient.class
(code)
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://localhost/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);
(/code)
Okies now you have my code ill start with the first error
1. When i try to rmic calculatorimpl i get this error:
error: Class calculatorimpl not found.
2. I read somwhere that it auto creates the stubs for you, so i tried running: rmiregistry which ran up fine
so i ran the server and got this:
Trouble: java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:
java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is:
java.lang.ClassNotFoundException: Calculator
can you please help

Answer 1

Code tags are with brackets [] not ().
You need to specify a classpath either as an ENVIRONMENT value (CLASSPATH=) or with the command line when you start your application (-cp).
Then you are going to need a policy file or you'll get security errors. Use the standard "policy all" file found in the documentation.
grant {
    permission java.security.AllPermission "", "";
};start java
-Djava.security.manager
-Djava.security.policy=%YOUR_HOME%\Security\policy.all
-cp %YOUR_HOME%
name_of_your_class