Starting a new Forum

Java on Mobile Devices J2ME
#1

Hi everybody

That's great. This post will be the first for a new forum, and it will be mine  :)

Let's start with some intersting URLs:

    http://www.midletcentral.com 

    http://www.cheekywireless.com/products.htm

http://www.geocities.com/srdjan_susnic/j2me_games/bay/index.html

Bye.

#2

Let’s get this J2ME forum rolling!

How many here have had experience in creating J2ME games for cellphones and/or palmtops? Please, recycle your thoughts!

What are your thoughts concerning development for such a yet “limited” platform?

What are your experiences when it comes to common pitfalls, compatibility problems or hardware limitations?

I’m a n00b Java developer student planning to spend the next couple of months digging into J2ME and hopefully end up with something playable…my journey starts here and now.

/Uffie

#3

Hi

I have done two small games for J2ME (DespullatMID,PetaBolas). You can find a shareware version in http://www.middletcentral.com.

Before you start with J2ME, I recomend to play a little with java applets. The best way to develop a J2ME game is first to develop the applet's game and then make the translation to J2ME.

I should recomend not to use float operations in your game design because J2ME don’t support them :frowning: Don’t use MouseListener, it’s better to use keyListener in this case. Instead of Panel try to use Canvas for your graphics, it will work faster and there is no Panel in J2ME.

Because the limited resources of movile phone don’t use recursive algorithms because you can run out of stack and it consums to much CPU’s time.

I know that there are a lot of limitations, but you have to think that your game could reach many, many, many people. Just imagine that your game is as succesful as Snake’s game. Think about it.

I have to recomend you to download from http://www.middletcentral.com a game called Arena v.1.1.0 from JavaXpert Ltd. It’s awsome what someone can do with so few machine resources.

Well, I hope that this will help you a little.

Bye.

#4

Very interesting comments, thank you!

I’ve read a while back that the big achilles heal in mobile development is the non standard in mobile devices (different LCD resolutions etc).
Even with the CLDC/MIDP profiles, is that still an issue to deal with? Do I in advance have to worry about what cellphone model to develop for, or is it possible to make games fully generic or even adapt to different hardware?

#5

You’re right about the Achilles heel.

Apart from LCD screen resolutions, there are other factors like

  • amount of heap memory,
  • maximum size of MIDlets,
  • processor speed,
  • UI conventions,
  • vendor-specific interpretation of J2ME,
  • vendor-specific API, and
  • vendor-specific bugs :stuck_out_tongue:

For example, thought Siemens M50 and the Nokia 3410 have nearly the same LCD dimensions, the M50 allows fairly large MIDlets (70K, AFAIK), while the 3410 allows only 30K. On the other hand, the M50 is one of the slowest phones around, and doesn’t have a compacting garbage collector. Then, these two phones also differ in their handling of images which are larger than the screen ~ M50 scales it to the screen size >:( while 3410 allows it to exists as it was.

Because of differences like these, porting a game is a non-trivial task, even between phones which externally look nearly identical. So, it is very important to pick your target platform carefully before you start on a game project. :slight_smile:

#6

Hi

There are good new about wireless devices. With the next powerful generation of SmartPhones and wireless devices we can work with the J2SE applications instead of J2ME. SavaJe OS is an advanced operating system which objective is movile devices.

   http://www.savaje.com/