RMI classcast exception

[Deepika Gupta]

I am getting this exception at the server side.Can anybody tell me what could be the problem?

java.lang.ClassCastException: cannot assign instance of ApplicationServer_Stub to field ServerSession.aAppServer of type ApplicationServer in instance of
ServerSession

Thanks
Deepika

[Nitesh Kant]

Hi Deepika,

Welcome to javaranch.

One gets a ClassCastException when you try to cast an instance to a type that it does not belong to.
You will also have a stack trace that will tell you exactly where the problem is.
If you can not, please post the stack trace and the relevant code.

[Deepika Gupta]

Thanks Nitesh for the reply

Actually I am aware of the fact that ClassCast exception comes when we try to cast a type with some wrong one.But i am not getting it in this case of rmi.The full trace is given below which happens at the server

From the client when i am calling this method. It fails at lApplicationServer.mGetUserSessions().iApplicationServer is a remote interface.

public static boolean ActiveSession(String name){
iApplicationServer lApplicationServer = mGetApplicationServer();

try{
Vector lVecSessions = lApplicationServer.mGetUserSessions();
return true;
}
}catch(Exception e)
{
System.out.println("Exception in ActiveSession: "+e.getMessage());
e.printStackTrace();
}
return false;

}

Now at the server side,this code will be executed

public java.util.Vector mGetUserSessions()
throws RemoteException
{
Vector lVecSessions = new Vector();

synchronized (aSessions)
{

try
{
for (int i = 0; i < aSessions.size(); i++)
{
iServerSession lServerSession = (iServerSession)aSessions.elementAt(i);
cUserSession lUserSession = new cUserSession(lServerSession);

lVecSessions.add(lUserSession);
}
}
catch (Exception pEx)
{

}
}
return lVecSessions;
}

iServerSession is also a remote interface. and ServerSession implements it. It has a field ApplicationServer aAppServer.iApplicationServer is also a remote interface and AppliactionServer implements it.

java.lang.ClassCastException: cannot assign instance of ApplicationServer_Stub to field ServerSession.aAppServer of type ApplicationServer in instance of
ServerSession

Exception in ActiveSession: cannot assign instance of

ApplicationServer_Stub to field ServerSession.aAppServer of type ApplicationServer in instance of ServerSession

java.lang.ClassCastException: cannot assign instance of

ApplicationServer_Stub to field ServerSession.

aAppServer of type ApplicationServer in instance of
ServerSession

at java.io.ObjectStreamClass$FieldReflector.setObjFieldValues(ObjectStre

amClass.java:1977)

at java.io.ObjectStreamClass.setObjFieldValues(ObjectStreamClass.java:11

57)

at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:19

18)

at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1836)



at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1

713)

at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1299)

at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:19

12)

at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1836)



at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1

713)

at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1299)

at java.io.ObjectInputStream.readArray(ObjectInputStream.java:1628)

at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1293)

at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:19

12)

at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1836)



at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1

713)

at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1299)

at java.io.ObjectInputStream.readObject(ObjectInputStream.java:339)

at sun.rmi.server.UnicastRef.unmarshalValue(UnicastRef.java:290)

at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:139)

at ApplicationServer_Stub.mGetUserSessions(

Unknown Source)

at RepositoryContainer.ActiveSession(Reposit

oryContainer.java:81)

at UpdateDataThread.run(UpdateDataThread.java:71)

Thanks