Introduction to JMA - Aud. 3

You may find the slides from the lecture here

• 17:00 - 17:50: Course overview, Optimization
• 18:00 - 19:00: Optimization, J2ME Coding

Reading

• Item 4 and 5 in Effective Java p. 13-19
• Chapter 6 in MIDP 2.0 Style Guide p. 53-69
• Wireless Development Tutorial Part I
• A Survey of J2ME Today

Homework for February 8

If you are in doubt about your Java programming skills you may try these two tests: short test and longer test. If you have trouble completing these tests then you should consider improving your Java skills before taking this course.

1. Make sure that the "J2ME Wireless Toolkit version 2.1" is installed on the computer where you want to do the programming assignments and experiments for this course. The toolkit is free and can be downloaded from here.

2. A simple Hello World program can be downloaded here. Use the "J2ME Wireless Toolkit" to compile and run this program. Modify HelloWorld so it displays the string "Hello <YOUR NAME>".

3. The HelloWorld program uses a class Textbox to define the string that is displayed. Find the on-line documentation of the MIDP API (part of the J2ME Wireless Toolkit). Get an overview of all the methods available. Is there a method for determining whether the device running an application has a color display?

4. Locate the methods available in the TextBox class. Find the correct method to print out how many chars you have written so far and how many available chars you have - e.g. add a print statement like: Used x out of xx (write to the console window not the display).

5. The user may change the contents of the TextBox on the diplay. Try it.
   Is it possible to retrieve (read) the changed text (string) from the program? If yes, how would you program this.

Links

Background on mobile communication