gnu.cajo.utils.extra

Class Registry

java.lang.Object

gnu.cajo.utils.extra.Registry

public final class Registry
extends Object

This class runs as a server. It allows remote VMs to register an object reference with it. Ideally, many instances of the servers would be running on the network. To keep the server memory footprint manageable, only one object is allowed per virtual machine IP address, any subsequent entries overwrite the previous. It also runs a lightwieght task, which periodically runs through the registry, purging object references that have become invalid. To encourage spontaneous internetworking, the registry will announce itself hourly, on the cajo hailing frequency, and listen on it, for other reference announcements; which it will automatically register.

Version:

1.0, 11-Oct-04 Initial release

Author:

John Catherino

Constructor Summary

Constructors

Constructor and Description
Registry()

Method Summary

Methods

Modifier and Type	Method and Description
Hashtable	get() This method is called by remote VMs, to request a copy of the remote object reference registry.
String	getDescription() Always a good idea; this method describes how to use the registry object, and what its features are.
static void	main(String[] args) This method is used to start up the registry server.
void	multicast(Multicast multicast) This method is called solely by this registry's Multicast member object, to register objects of remote server announcements.
void	post(RemoteInvoke ref) This method statically called by a remote machine to register an object reference.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Registry

public Registry()

Method Detail

multicast

public void multicast(Multicast multicast)

This method is called solely by this registry's Multicast member object, to register objects of remote server announcements.

post

public void post(RemoteInvoke ref)
          throws ServerNotActiveException

This method statically called by a remote machine to register an object reference.

Parameters:

ref - The remote reference to the object to be registered

Throws:

ServerNotActiveException

get

public Hashtable get()

This method is called by remote VMs, to request a copy of the remote object reference registry.

Returns:

A hashtable containing all the references, keyed by their server addresses

getDescription

public String getDescription()

Always a good idea; this method describes how to use the registry object, and what its features are. Not unlike these comments themselves.

Returns:

A string destribing this server object

main

public static void main(String[] args)

This method is used to start up the registry server. It will announce its startup on the hailing frequency, to allow linkage to other registries, before starting to listen on it, for new announcements.

Note: to build this application, it will also require an RMI stub class for Remote. This means you must also run the following instruction:

rmic -v1.2 gnu.cajo.invoke.Remote

Parameters:

args - If the server is behind a NAT router, the only argument should be the network address used outside the router. Otherwise provide nothing, and it will use the default local address.