In both client and server classes, I have an exact same inner class called Data. This Data object is being sent from the server using:
ObjectOutputStream output= new ObjectOutputStream(socket.getOutputStream());
output.writeObject(d);
(where d is a Data object)
This object is received on the client side and cast to a Data object:
ObjectInputStream input = new ObjectInputStream(socket.getInputStream());
Object receiveObject = input.readObject();
if (receiveObject instanceof Data){
Data receiveData = (Data) receiveObject;
// some code here...
}
I'm getting a java.lang.ClassNotFoundException: TCPServer$Data on this line Object receiveObject = input.readObject();
My guess is that it's trying to to look for the Data class in the Server side and can't find it, but I'm not sure... How do I fix this?
What you were trying to do is something along the lines of the following:
class TCPServer {
/* some code */
class Data {
}
}
class TCPClient {
/* some code */
class Data {
}
}
Then you are serializing a TCPServer$Data and trying to unserialize it as a TCPClient$Data. Instead you are going to want to be doing this:
class TCPServer {
/* some code */
}
class TCPClient {
/* some code */
}
class Data {
/* some code */
}
Then make sure the Data class is available to both the client and the server programs.
When you use some class in two different JVMs, and you are marshalling/unmarshalling the class then the class should be exported to a common library and shared between both server and client. Having different class wont work any time.
What you are trying to do is marshall TCPServer$Data and unmarshall as TCPClient$Data. That is incompatible.
来源：https://stackoverflow.com/questions/11745771/objectinputstream-readobject-classnotfoundexception