COMP 310 Spring 2010	Lec25:  RMI...

The code has been updated to enable the GUI's to be edited using Jigloo.   Please download the new version!  

Continuing our discussion of the remote task execution example...

1. RegistryFactory:
   • Has static services for creating and/or locating the Registry for the client and server use.
   • Uses techniques for composing lambdas to enable the methods to send multiple messages to multiple output targets.
2. Exchange of stubs to establish views of client and server on each other:
   • client and server can talk directly to each other's views.
3. Serialization:
   • See Pi.java code
   • Serializable interface tells the compiler that this object can be serialized, i.e. its data (not its code!) can be turned into a byte stream and sent over the network.
     • Code, if needed, is transmitted separately and automatically.   The client's java.rmi.server.codebase value is imbedded in the serialized byte stream.   The receiver Java class loader will look at this value and find the class file server on the sender and then issue an http-type request to download the associated class file.
     • Note that the class file server does not have to be co-located with the serialized object's sender.   The class file server can be a separate machine altogether, e.g. a central class file repository.
   • transient fields are not serialized.
   • Optional readObject method is used for custom deserialization processes, here to reinitialize the transient taskView field.   The server will attach its own ITaskView adapter so the transmitted task can communicate to the server.
4. TCP ports used:
   • IRMI_Defs.REGISTRY_PORT - used by the Registry.  Inbound on the server.
   • IRMI_Defs.CLASS_SERVER_PORT_A - Part of java.rmi.server.codebase which tells what port on the server where the class files can be downloaded from.   The port the class file server is attached to.   Inbound on the server.
   • IRMI_Defs.CLASS_SERVER_PORT_B - Same as IRMI_Defs.CLASS_SERVER_PORT_A but for the client.
   • ITextAdapater.BOUND_PORT_A - The port the compute engine and the view adapter back to the server are bound to.  Inbound on the server.
   • ITextAdapater.BOUND_PORT_B - The port the view adapter back to the client is bound to.  Inbound on the client.

© 2010 by Stephen Wong