Groovy Jabber-RPC


{link:Jabber-RPC|http://www.jabber.org/jeps/jep-0009.html}{link}


allows you to make XML-RPC calls using the Jabber protocol

. Groovy has a Jabber-RPC implementation which allows you to create a local Jabber-RPC server and to make calls on remote Jabber-RPC servers. Jabber servers are widely available and very easy to set up and run. The Google GTalk service uses Jabber and the Groovy Jabber-RPC package works over GTalk.
We use the excellent

{link:Smack|http://www.jivesoftware.org/smack/}{link}


Jabber library from Jive Software to handle the protocol details.

The Server

It's really easy to set up a server which provides a set of remotely callable functions.

  1. Create a server object 
    import groovy.net.xmlrpc.*
import org.jivesoftware.smack.XMPPConnection

    def server = new JabberRPCServer()

  2. Add some methods 
    sever.echo = {return it}  // the closure is now named "echo" and is remotely callable

  3. Start the server 
    def serverConnection = new XMPPConnection("talk.example.org", 5222, "example.org")
    serverConnection.login("myServerId", "myServerPassword")   // logging in as myServerId@example.org
    server.startServer(serverConnection)

  4. You're done!

The Client

It's pretty easy to make the remote calls too

  1. Create a proxy object to represent the remote server 
    def clientConnection = new XMPPConnection("talk.example.org", 5222, "example.org")
    clientConnection.login("myClientId", "myClientPassword")   // logging in as myClientId@example.orgm
    def serverProxy = new JabberRPCServerProxy(clientConnection, "myServerId")

  2. Call the remote method via the proxy 
    println severProxy.echo("Hello World!")

  3. As long as myClientId@example.org and myServerId@example.org are buddies then the call will be made and the result returned