Programming Jabber

Looking at JabberRPCResponder Step by Step

Now let’s examine the JabberRPCResponder script step by step so we can see how it works:

import org.jabber.jabberbeans.*;
import org.jabber.jabberbeans.Extension.*;
import org.jabber.jabberbeans.util.JID;
import java.net.InetAddress;
import java.util.Enumeration;
import java.io.*;
import helma.xmlrpc.*;

We need to bring in the jabberbeans classes as shown, as well as some core Java features that we’ll see used in the script a bit later: an InetAddress to represent the Jabber server’s hostname, an Enumeration interface to access the extensions in the incoming IQ elements, and java.io features for feeding the XML-RPC-encoded requests to the XmlRpcServer object. We also bring in the classes from the Helma XML-RPC library.

public class JabberRPCResponder implements PacketListener
{
  private String server   = "gnu.mine.nu";
  private String user     = "server";
  private String pass     = "pass";
  private String resource = "jrpc-server";

  private XmlRpcServer responder;

  private ConnectionBean cb;

The definition of our JabberRPCResponder class looks similar to that of the HostAlive class in Section 8.2. However, rather than merely connecting to a Jabber server and sending packets off down the stream, we want to listen for incoming packets—in this case, IQ elements carrying jabber:iq:rpc-qualified payloads—and handle them. Accordingly, we specify that our main class implements PacketListener, a JabberBeans interface that Jabber clients use to receive notification ...