Notes

Client and Server Objects:

The client initiates communication by using a client-side stub to make a request of a remote object.
The server object receives this request through a server-side object skeleton.
Client-Side Invocation:

A client initiates an RMI invocation by calling a method on a stub object.
The stub maintains an internal reference to the remote object and forwards the method invocation request through the Remote Reference Layer (RRL).
Marshaling:

Marshaling involves converting local objects into a portable form so they can be transmitted to a remote process.
Remote objects implementing the java.rmi.Remote interface use their remote reference as marshaled data.
If an object is not a Remote object but is Serializable, it is serialized into bytes and sent to the remote host.
If an object is neither Remote nor Serializable, a java.rmi.MarshalException is thrown.
Client-Side Remote Reference Layer:

If marshaling is successful, the client-side remote reference layer receives the remote reference and marshaled arguments from the stub.
Network Communication:

The remote reference layer converts the client request into low-level RMI transport requests and sends it over the network to the sole remote object.
Server-Side Remote Reference Layer:

On the server, the server-side remote reference layer receives the transport-level request and converts it into a request for the server skeleton.
Server Skeleton:

The skeleton converts the remote request into the appropriate method call on the actual server object.
Unmarshaling is performed to convert method arguments into the server environment.
Method Execution on Server:

The server object executes the method call, and if a return value or an exception is generated, the skeleton marshals the object for transport back to the client.
Return to Client:

The result is sent back using the appropriate transport protocol.
The result passes through the client reference layer and stub, is unmarshaled by the stub, and is finally handed back to the client thread that invoked the remote method.