JaGD - Mobile Photo Treasure Hunt for J2ME phones

JaGD is a photo oriented learning and gaming platform for mobile phones. You can find more information on a poster which was presented at Ubicomp 2005 (paper, poster). The JaGD system is implemented as a client server system. It includes a backend system and clients that run on mobile phones.

The backend is implemented in Java (Servlets) on a Tomcat server. It includes a game editor, a viewer, user management, and voting. The games created with the editor are available for download over HTTP. The upload of pictures to the server can be done over HTTP as well.
For the mobile phone a standalone application is implemented as a MIDlet. The MIDlet is the platform that downloads a game description over HTTP and runs then the game. During the game the user can be off-line. After finishing all tasks the locally stored pictures are uploaded to the sever by the MIDlet. The application on the client side uses the J2ME API and currently works on the Nokia 6600 (Java 2 Micro Edition, MIDP 2.0, CLDC 1.0). Game instructions are provided as XML documents by the server and therefore have to be parsed on the mobile client. We used kXML as a small pull parser that is designed for use in MIDP environments. The parsed values, user data and photos are saved in record stores. The built-in camera of the mobile phone is controlled using the Mobile Media API (JSR 135). To provide an individual look-and-feel, the UI is composed of customized items.

Server

In the game creation process the author gives the game a title and provides a short description of its purpose. It can be defined if the tasks have to be performed in the order set by the author or if users can do it in an order they want. Then the tasks are described, each with a short explanation. For each task the author can specify the number of pictures that can be taken and how many points one gets for this task.
Overview for a Munich city game:

Requirements

• Installed Tomcat or any other servlet server
• Installed MYSQL database
  For your first test you can use our database.
  IP: 141.84.8.96
  Port: 33006
  DBname: pmeg2
  DBuser: pmeg2
  Password: j.2.m.e.
  MYSQL package mysql-connector-java-3.0.16 or higher (you can find it in the director /mysqldriver/) needs to be installed on your server
• The code is provided as an Netbeans 4.1 project (you should install Netbeans 4.1. and the Netbeans Mobility Pack).

Install files

1. Install jagd.war via your Tomat Manager (or any equivalent)
2. Copy all files from the jagd folder to the Folder you want it to be on your Tomcat server

Install database

• go to your install directory and call the Install Servlet (e.g. http://www.yourhost.com/jagd/Install) -- no .html and capital "I" Here you can use the database facts mentioned before.
• Follow the instructions on the screen.

Source code

• jagd/css/: contains the css file for the web page
• jagd/images/: the images for the web page
• jagd/META-INF/: meta information for the tomcat server. Actually it only contains the name of the servlet which is also used as the root element.
• jagd/uploads/: contains the images, uploaded by the users
• jagd/WEB-INF/ Is the default folder for Tomcat projects. Everything inside this folder can'T be directly opened by a visitor of the web page.
  • classes: contains the classes. e.g. the servlet classes.
  • dbsdata: contains the xml file that stores the conenctio data for the mysql server.
  • doc and lib: empty
  • templates: contains the html template files

Client

When playing the game the tasks created with the editor are displayed on the phone. In case the game author decides that they need to be completed in order the user only can select the next task otherwise the user can freely choose which task to do.

When all tasks are completed or the time is up the user can upload the pictures. On the server the pictures are presented for other participants in the game to look and vote.

Used Software

• Eclipse IDE (tested with version 3.1)
• EclipseME plugin, can be installed via "Help-->Software Updates" in Eclipse
• Wireless Toolkit (WTK) (e.g. Nokia Developers Suite for J2ME

Used Hardware

• J2ME
• MIDP 2.0
• CLDC 1.0
• Mobile Media API (JSR-135)

Application

• connection: contains the classes that do the upload over HTTP and the base 64 encoding
• controller: contains interfaces and classes that implement the game logics
• model: contains classes that represent the parts of a game (game, task, picture, user)
• view: contains all classes that implement the ui (forms, custom items, canvases, action handler)
  (Quite large as several methods did not work properly on the Nokia 6600 and a lot of workaround is done in here.)