ClassNotFoundException (error in lookup : stub not found by client) ??

Question

SampleServer.java_
import java.rmi.*;
public interface SampleServer extends Remote
public int sum(int a,int b) throws RemoteException;
SampleServerImpl.java_
import java.rmi.*;
import java.rmi.server.*;
import java.rmi.registry.*;
public class SampleServerImpl extends UnicastRemoteObject implements SampleServer{
SampleServerImpl() throws RemoteException
super();
public int sum(int a,int b) throws RemoteException
return a + b;
public static void main(String args[])
//set the security manager
try
// System.setSecurityManager(new RMISecurityManager());
//create a local instance of the object
SampleServerImpl Server = new SampleServerImpl();
//put the local instance in the registry
Naming.rebind("SAMPLE-SERVER" , Server);
System.out.println("Server waiting.....");
catch (java.net.MalformedURLException me)
System.out.println("Malformed URL: " + me.toString());
catch (RemoteException re)
System.out.println("Remote exception: " + re.toString());
SampleClient .java_
import java.rmi.*;
import java.rmi.server.*;
public class SampleClient
public static void main(String[] args)
// set the security manager for the client
//System.setSecurityManager(new RMISecurityManager());
//get the remote object from the registry
try
System.out.println("Security Manager loaded");
String url = "rmi://172.16.5.41:1099/SAMPLE-SERVER";
SampleServer remoteObject = (SampleServer)Naming.lookup(url);
System.out.println("Got remote object");
//narrow the object down to a specific one
//System.out.println("Location: " + System.getProperty("LOCATION"));
// make the invocation
System.out.println(" 1 + 2 = " +
remoteObject.sum(1,2) );
catch (RemoteException exc)
System.out.println("Error in lookup: " + exc.toString());
catch (java.net.MalformedURLException exc)
System.out.println("Malformed URL: " + exc.toString());
catch (java.rmi.NotBoundException exc)
System.out.println("NotBound: " + exc.toString());
errors_
Error in lookup : java.rmi.UnmarshalException :error unmarshalling return;
nested exception is : java.lang.ClassNotFoundException :SampleServerImpl_Stub
dynamic code loading is not working in the client.
the server is working fine.
thanks

Answer 1

yeah.i have my codebase files D: drive on windows .when running the server i used
java  -Djava.rmi.server.codebase=file://d:/ -Djava.security.policy=policy.all SampleSeverImpli got these errors
Exception in thread "main" java.security.AccessControlException: access denied (
java.io.FilePermission \\d read)
        at java.security.AccessControlContext.checkPermission(AccessControlConte
xt.java:323)
        at java.security.AccessController.checkPermission(AccessController.java:
546)
        at java.lang.SecurityManager.checkPermission(SecurityManager.java:532)
        at java.lang.SecurityManager.checkRead(SecurityManager.java:871)
        at java.io.File.exists(File.java:731)
        at sun.net.www.protocol.file.Handler.openConnection(Handler.java:80)
        at sun.net.www.protocol.file.Handler.openConnection(Handler.java:55)
        at java.net.URL.openConnection(URL.java:945)
        at sun.rmi.server.LoaderHandler.addPermissionsForURLs(LoaderHandler.java
:1021)
        at sun.rmi.server.LoaderHandler.access$300(LoaderHandler.java:52)
        at sun.rmi.server.LoaderHandler$Loader.<init>(LoaderHandler.java:1129)
        at sun.rmi.server.LoaderHandler$Loader.<init>(LoaderHandler.java:1110)
        at sun.rmi.server.LoaderHandler$1.run(LoaderHandler.java:865)
        at java.security.AccessController.doPrivileged(Native Method)
        at sun.rmi.server.LoaderHandler.lookupLoader(LoaderHandler.java:862)
        at sun.rmi.server.LoaderHandler.loadClass(LoaderHandler.java:385)
        at sun.rmi.server.LoaderHandler.loadClass(LoaderHandler.java:165)
        at java.rmi.server.RMIClassLoader$2.loadClass(RMIClassLoader.java:620)
        at java.rmi.server.RMIClassLoader.loadClass(RMIClassLoader.java:247)
        at sun.rmi.server.MarshalInputStream.resolveClass(MarshalInputStream.jav
a:197)
        at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:157
5)
        at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1496)
        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1
732)
        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351)
        at sun.rmi.registry.RegistryImpl_Skel.dispatch(Unknown Source)
        at sun.rmi.server.UnicastServerRef.oldDispatch(UnicastServerRef.java:386
        at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:250)
        at sun.rmi.transport.Transport$1.run(Transport.java:159)
        at java.security.AccessController.doPrivileged(Native Method)
        at sun.rmi.transport.Transport.serviceCall(Transport.java:155)
        at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:5
35)
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTranspor
t.java:790)
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport
.java:649)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExec
utor.java:885)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor
.java:907)
        at java.lang.Thread.run(Thread.java:619)
        at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(Unknow
n Source)
        at sun.rmi.transport.StreamRemoteCall.executeCall(Unknown Source)
        at sun.rmi.server.UnicastRef.invoke(Unknown Source)
        at sun.rmi.registry.RegistryImpl_Stub.rebind(Unknown Source)
        at java.rmi.Naming.rebind(Unknown Source)
        at SampleServerImpl.main(SampleServerImpl.java:27)when i used just java -Djava.security.policy=policy.all SampleServerImpl
everythin was fine at the server .
it gave the output Server waiting...
but at the client i got these errors when i tried
java -Djava.rmi.server.codebase=file://d:/ SampleClient   or   java -Djava.security.policy=policy.all SampleClient
C:\>java -Djava.security.policy=policy.all SampleClient
Security Manager loaded
Exception in thread "main" java.security.AccessControlException: access denied (
java.net.SocketPermission 172.16.5.41:1099 connect,resolve)
        at java.security.AccessControlContext.checkPermission(Unknown Source)
        at java.security.AccessController.checkPermission(Unknown Source)
        at java.lang.SecurityManager.checkPermission(Unknown Source)
        at java.lang.SecurityManager.checkConnect(Unknown Source)
        at java.net.Socket.connect(Unknown Source)
        at java.net.Socket.connect(Unknown Source)
        at java.net.Socket.<init>(Unknown Source)
        at java.net.Socket.<init>(Unknown Source)
        at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(Unknown S
ource)
        at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(Unknown S
ource)
        at sun.rmi.transport.tcp.TCPEndpoint.newSocket(Unknown Source)
        at sun.rmi.transport.tcp.TCPChannel.createConnection(Unknown Source)
        at sun.rmi.transport.tcp.TCPChannel.newConnection(Unknown Source)
        at sun.rmi.server.UnicastRef.newCall(Unknown Source)
        at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
        at java.rmi.Naming.lookup(Unknown Source)
        at SampleClient.main(SampleClient.java:16)172.16.5.41 was my server.the rmiregistry was running on the same machine on which the server was running