Software CS2310 Engineering Final Project Report
by Strasa Acimovic
Spring 2006
Project Description
This project became something I didn't expect in many ways. My initial proposal was to translate some java strings in an existing project into XML. Upon learning this and doing research my project definition started including current XML messaging standards, eventually the Jabber supported XMPP protocols, and finally Jabber servers and clients. This changed from a simple code alteration to a more research intensive project with possibilities for future study.
Project Progress
The project progressed through several stages. 1. VC analysis The first step was to get the current VC code and study it. I pulled it apart, identified its messaging structures, and began to study how to translate XML parsing in java. 2. XML Parsing in Java The first portion of the project I began to study the Java XML native libraries, and realized that I needed more powerful tools in order to manipulate the language. I chose to use the http://www.jdom.org/ JDOM libraries for this. I taught myself their codebase and began to work on a VC translation. 3. XML Messaging Protocol There already exists a widely used XML messaging protocol called XMPP. The Jabber client (used by many people) is built upon it and its recent popularity has skyrocketed as its implementation in the famous GoogleTalk has been used. Although I discussed using this with some of my classmates, the go-ahead was given to begin pursuing this implementation. 4. XMPP Libraries To accomplish my new goals I had to study the libraries provided for jabber, and upon discussion again with a few of my classmates I decided on the jabber SMACK api. The upshot of this was that it was easy to use, high level (making future projects or modifications easy), and intuitive as well as open under the GPL. The SMACK api folks provided a server (Wildfire) and a client (SPARK) but only Wildfire was open source. David pursued that as his server source, but I had to find a different implementation that I could use for my project. 5. Jbother Jbother is an existing Open Source project that implements the smack API. I pulled it to my ends and began studying it extensively since at this point I was looking forward to the future. I was hoping to establish this as a possible launching pad for further projects.
Current Status
The current incarnation of the project is fairly close to the Jbother implementation. One of the primary goals of the project were to establish classroom like chat rooms that provide certain
functionalities (person-to-person chat, classrooms that only allow in registered students, status indicated by smilies, group and chat). I worked with David to insure that our current code generation enables all this and provides a platform for future expandibility.
Directions
Simply extract the folder (using the tar -xzvf command in unix). You can build from source using the ant command in the top level. The source code is provided in /src/valhalla/. Authentication and user registration can be done directly from the client no external web-sign up is necessary.
Plugins
I haven't had much time to work with the plugins yet, but the jbother forums are very active and the creator is quick to answer emails. All plugins are jar files. In the jar root, there needs to be a file called "plugin.properties" that contains information about the plugin. Here is an example for the SysTrayPlugin:
mainClass = com.valhalla.jbother.plugins.SystrayPlugin description = Adds system tray icon for Linux name = Systray Plugin APIVersion = 91212 version = 0.0.2b author = Yury Soldak releaseDate = Jan 10, 2005 os = Linux arch = i386
The main class needs to implement the Plugin interface (documentation here). If you want to listen for events, you also need to implement the PluginEventListener interface (documentation here). To listen for events, add the plugin to the plugin chain in the plugin's init() method. An exmaple is this:
/** * Initializes plugin * @return true on success */ public boolean init() { PluginChain.addListener( this ); initComponents(); com.valhalla.Logger.debug( "Systray plugin initiated" ); return true; }
All events are recieved by all plugins, so you just need to test for ...