Trouble with first RMI

Question

Hi,
I just have written a simpliest RMI application with a help of a textbook.
When I run both parts (server & client) on the same machine I get the expected output, but when I tried to run client on another machine - I got
java.rmi.UnmarshalException: error unmarshalling return; nested exception is:
java.lang.ClassNotFoundException: SimpleRMIImpl_Stub (no security manager: RMI class loader disabled)
I guess (no security manager: RMI class loader disabled) is the answer to my problem. But have no idea what with means and what should I do??
C:\distr>java SimpleRMIClient my_other_machine
java.rmi.UnmarshalException: error unmarshalling return; nested exception is:
java.lang.ClassNotFoundException: SimpleRMIImpl_Stub (no security manager: RMI class loader disabled)
at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
at java.rmi.Naming.lookup(Unknown Source)
at SimpleRMIClient.main(SimpleRMIClient.java:13)
Caused by: java.lang.ClassNotFoundException: SimpleRMIImpl_Stub (no security m
ager: RMI class loader disabled)
at sun.rmi.server.LoaderHandler.loadClass(Unknown Source)
at sun.rmi.server.LoaderHandler.loadClass(Unknown Source)
at java.rmi.server.RMIClassLoader$2.loadClass(Unknown Source)
at java.rmi.server.RMIClassLoader.loadClass(Unknown Source)
at sun.rmi.server.MarshalInputStream.resolveClass(Unknown Source)
at java.io.ObjectInputStream.readNonProxyDesc(Unknown Source)
at java.io.ObjectInputStream.readClassDesc(Unknown Source)
at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
at java.io.ObjectInputStream.readObject0(Unknown Source)
at java.io.ObjectInputStream.readObject(Unknown Source)
... 3 more
C:\distr>

Answer 1

Hello friend,
I have the same problem have posted above, and I have try all them have showed but no way! so try my self.
I will write in detail so you can understand our problem. but I am sorry, this is only for Windows
This is may example from abook:
Reverse.java file
import java.rmi.*;
import java.rmi.server.*;
public class Reverse extends UnicastRemoteObject implements ReverseInterface
public Reverse() throws RemoteException
super();
public String reverseString(String originalString) throws RemoteException
int length = originalString.length();
StringBuffer temp = new StringBuffer(length);
for (int i = length ; i>0 ; i--)
temp.append(originalString.substring(i-1,i));
return temp.toString();
public static void main(String[] args)
if (System.getSecurityManager() == null)
System.setSecurityManager(new RMISecurityManager());
//String name = "//jamesh/com.wrox.rmi.Reverse";
String name = "//localhost/Reverse";
try
Reverse r = new Reverse();
Naming.rebind(name,r);
System.out.println("Reverse object bound");
catch (Exception e)
System.out.println("Error while binding Reverse object");
System.out.println(e.toString());
and ReverseInterface.java file
import java.rmi.Remote;
import java.rmi.RemoteException;
public interface ReverseInterface extends Remote
String reverseString(String originalString) throws RemoteException;
and there is the client file for testing, Client.java
import java.rmi.*;
//import ReverseInterface;
public class Client
public static void main(String[] args)
try
//ReverseInterface ri = (ReverseInterface) Naming.lookup("//localhost:1099/Reverse");
ReverseInterface ri = (ReverseInterface) Naming.lookup("//localhost:1099/Reverse");
String result = ri.reverseString(args[0]);
System.out.println("The reverse of " + args[0] + " is " + result);
catch (Exception e)
System.out.println("Error accessing remote object.");
System.out.println(e.toString());
this is .java.police file
/* AUTOMATICALLY GENERATED ON Tue Jan 13 12:55:40 GMT+07:00 2004*/
/* DO NOT EDIT */
grant codeBase "file:${java.home}/lib/ext/*" {
permission java.security.AllPermission;
grant {
permission java.lang.RuntimePermission "stopThread";
permission java.net.SocketPermission "localhost:1024-", "listen";
permission java.util.PropertyPermission "java.version", "read";
permission java.util.PropertyPermission "java.vendor", "read";
permission java.util.PropertyPermission "java.vendor.url", "read";
permission java.util.PropertyPermission "java.class.version", "read";
permission java.util.PropertyPermission "os.name", "read";
permission java.util.PropertyPermission "os.version", "read";
permission java.util.PropertyPermission "os.arch", "read";
permission java.util.PropertyPermission "file.separator", "read";
permission java.util.PropertyPermission "path.separator", "read";
permission java.util.PropertyPermission "line.separator", "read";
permission java.util.PropertyPermission "java.specification.version", "read";
permission java.util.PropertyPermission "java.specification.vendor", "read";
permission java.util.PropertyPermission "java.specification.name", "read";
permission java.util.PropertyPermission "java.vm.specification.version", "read";
permission java.util.PropertyPermission "java.vm.specification.vendor", "read";
permission java.util.PropertyPermission "java.vm.specification.name", "read";
permission java.util.PropertyPermission "java.vm.version", "read";
permission java.util.PropertyPermission "java.vm.vendor", "read";
permission java.util.PropertyPermission "java.vm.name", "read";
permission java.net.SocketPermission "*:1024-65535", "connect,accept";
permission java.net.SocketPermission "*:80", "connect";
grant {
permission java.security.AllPermission;
=======================end of code==============
then there is the guide for building this example
I save my example in:
ReverseInterface.java file and Reverse.java
c:\rmiexample
client.java in c:\rmiexample\test and the policy in c:\rmiexample\policy
1/Compile all class
javac *.java
2/ generate Stub and skeleton
rmi Reverse
3/ start RMI registry
start rmiregistry
4/execute remode object
java -classpath c:\rmiexample\ -Djava.rmi.server.codebase=file:/C:\rmiExample\ -Djava.rmi.server.hostname=localhost -Djava.security.manager -Djava.security.policy=file:/C:\rmiExample\policy\.java.policy Reverse
Reverse object bound
5/ Run client
java -classpath c:\rmiexample\test\ Client 123456789
The reverse of 123456789 is 987654321
If you system is config well you run it without any problem but, my computer have many problem with JVM, so I have to work very hard to pass this example ;-)
The first problem is that:
C:\rmiExample>java -classpath c:\rmiexample\test\ Client qerrewrw
Error accessing remote object.
java.rmi.UnmarshalException: error unmarshalling return; nested exception is:
java.lang.ClassNotFoundException: Reverse_Stub (no security manager: RMI class loader disabled)
the second error when i change, policy folowing the guide in the book,
C:\rmiExample>java -classpath c:\rmiexample\test\ Client qerrewrw
Error accessing remote object.
java.rmi.UnmarshalException: error unmarshalling return; nested exception
java.lang.ClassNotFoundException: access to class loader denied
as you see, I went to java.sun.com, I hope in there will help me pass my problem, but there are many guide, but you know , no thing fix with me... any way thank you very much, about the time you spend on writing the guide
and there is the last I do myself, chand policy to
grant {
permission java.security.AllPermission;
C:\rmiExample>java -classpath c:\rmiexample\test\ Client 123456789
The reverse of 123456789 is 987654321
of course , this is not the good solution, but I just want to show that to make it runfirst and will fine tune later.
I hope you run all easily...
vnnWeb.