The culprit appeared to be the fact that I set the roster to accept all subscription requests. The roster, in plain English, is the buddy list. Subscriptions mean that as my buddy, you can see my status. My code looked like this:

// set roster subscription mode
Roster roster = conn1.getRoster(); 
roster.setSubscriptionMode(Roster.SubscriptionMode.accept_all);
 
// wait for messages, accepting all of them
PacketFilter pf = new PacketTypeFilter(Message.class);
PacketCollector pc = conn1.createPacketCollector(pf);

I found that if I used JSJaC I had to be logged-in to the server as a buddy of the bot for the bot to get the messages I sent it. On the other hand, when I removed these lines from my code, any message was received — which is what you want from a bot. So, if you do NOT set your roster subscription mode, you will be open to get all messages…

Weird.

Fundamentally, a room already exists is the situation where a room is already set up on the server with the same name as the one you wish to create.

The MultiUserChat object has a static getRoomInfo() method which may have been the way to go. If the room does not exist, return null. Instead, if the room does not exist throws an XMPPException. Not sure what the error situation is here – I am just trying to find out if a room exists or not, but that causes an exception.

The flipside is on the creation end. If you try to create a room that already exists, an XMPPException will be thrown. This makes sense and is recoverable. Still, I am a fan of checking first instead of trying to do something only to encounter a bad situation. Not a biggie – just hope this spares someone the exploration and time. Not really documented, etc.

Could not find anything to require this in the XMPP specifications for multi-user chat.

Oddness.

UPDATE:
This is apparently the way it is supposed to be according to the XMPP protocol or as explained to me on the Openfire dev boards.

1. After joining a Multi-User Chat (MUC) independently, without invite, I was forbidden (e.g. error 403) from finding out who the administrators or owners of the room were. I could not find anything about this in the documentation.
   The workaround was not too bad: apparently the method getOccupant() allows you to get an Occupant object which does hold affiliation and can report admin rights.
2. In some situations – not sure when yet – the owner of an MUC was able to grant another user admin status by just using his/her nickname, without using the full JID. That is
   grantAdmin("nickname") worked just as well as grantAdmin("nickname@conference.server"). Nonetheless, when trying to use the method getOccupant() as mentioned above, the full JID form worked while the nickname-only one failed.

I am using Smack 3.0.4 and Openfire 3.5.2. Weird.

Only thing is that JSJaC is not the easiest to set up with Openfire.

JSJaC uses HTTP-binding, which according to Wikipedia allows for long-lasting HTTP requests instead of polling, which just periodically checks the server to see if there is a message waiting. To do that, JSJaC needs to connect to the server and that is done by accessing a somewhat tricky port, 7070 is the default in version 3.5.2. What’s tricky about it? Browsers do not like to let JavaScript access services using XMLHttpRequest, the lifeblood of AJAX, on URLs and ports unlike the one which the current URL relies on. This is normally solved using a proxy or a URL rewrite, which forward requests to the desired ports and pass back responses, all as if you used the ‘appropriate’ ports. Luckily, Apache’s HTTPd has great modules that do just that. The instructions in JSJaC’s readme file recommended using a rewrite. That caused repeated 503 errors from Apache. Using its proxy did work for me. As usual, you spend time, read here and read there, and finally, you normally find a way to make it work. This how I did it.

1. After downloading JSJaC, open jsjac.js. Change the line

   var JSJACHBC_USE_BOSH_VER=false;

   to
   

   var JSJACHBC_USE_BOSH_VER=true;

2. To allow Apache HTTPd’s proxy to work, enable proxy_module and proxy_http_module in Apache HTTPd’s httpd.conf file
3. Add a virtual host that will map a certain URL to the proxy, and set up the proxy to point at the Openfire http-binding port:

   <virtualhost 127.0.0.1:80>
   	DocumentRoot "C:/www/root"  <!-- This is the document root for your server -->
   	AddDefaultCharset UTF-8
   	ProxyRequests On
   	ProxyPass /http-bind/ http://127.0.0.1:7070/http-bind/ <!-- This is where your Openfire server can be accessed -->
   </virtualhost>

4. To test this configuration, use JSJaC’s simpleclient.html, its sample client, to try and connect to the server. Make sure you add the following line

   oArgs.authtype = 'nonsasl';

   above

   con.connect(oArgs);

5. Start Apache HTTPd and open simpleclient.js
6. simpleclient asks for 4 fields:
   • The server’s base URL: This is the proxied URL, for example, http://127.0.0.1/http-bind/ (note the trailing slash) in my case.
   • Server name/domain: The domain Openfire was set up to use. In XMPP, if the server’s name is myserver, users will be known on it with IDs like joe@myserver
   • User name of existing user
   • The password for that user
7. Connect!

I highly recommend using Firebug to ensure the request is sent properly and is being received properly from Openfire. Odd Firefox object initialization errors are due to the fact that an attempt is made to access a port JavaScript is not allowed to access.