Develop Blackberry apps using native API or J2ME?

Question

We're about to build a Blackberry application but would love some input on whether to implement using J2ME (MIDlet based) or Blackberry native (UIApplication).

I understand some of the tradeoffs. J2ME will be more flexible if we want to port the app to other devices. RIM has better support for Blackberry native.

The place I'm still lacking information, though, is on the UI side. We want to build an app that has a great user experience, and one that looks like other apps BB users are accustomed to. Can we do this if we go the J2ME route?

Apologies for the somewhat subjective and less technical nature of the question.

Answer 1

There is a way in between: You could use J2ME-Polish and code natively in J2ME. Polish will add the look and feel of a native BlackBerry app to some extent. That has the advantage of porting your app to other J2ME phones and not be limited to BlackBerry.

Answer 2

BlackBerry is a very difficult platform to program for. I went the native route and found it to be very poorly documented and overall just a miserable design to work with. I did feel it to be necessary because you will lose the ability for certain features (scroll wheel?) if you go the J2ME route. It's a tradeoff and you'll have to choose the one that fits better for your specific need.

Answer 3

I have been working with J2ME since 2002 when the Nextel/Motorola phones were in the forefront of J2ME functionality. I deal primarily with non-gaming applications. Today with J2ME evolving and more phones conforming to the JSRs my application continues to port smoothly. This year I finally got around to moving it to a Blackberry device. Two days later my application is fully functional on a Blackberry. The application is purely generic J2ME and uses many of the JSRs (location, bluetooth, xml, etc ). A strong UI design helps. I extended some of my UI classes to support the QWERTY/SureType keypads. I have used a variety of native applications found on Blackberry devices (not games) and I have yet to justify any reason to venture off to the RIM API to see what I would benefit. The arguments expressed above by other fellow programmers further prove that there is very little to gain unless you are purely devoted to a Blackberry device platform.

Answer 4

I've tried it both ways - building a pure MIDP app to run on BlackBerry and non-BLackBerry platforms and building a separate BlackBerry app (often using much of the same business-logic and networking code as the MIDP app). Definitely go the BlackBerry native route.

It's all about the BB UI classes. They'll give you the ability to (among other things) respond to the different type of menu events (trackball and menu key), respond to BB specific key codes, if you're interested in the Storm take advantage of the orientation sensor and touch support. Plus they're a much richer set of UI elements to work with. You can build up a lot (but not all) of what they do in pure MIDP, but end up customizing so much of it for each platform that you won't save anything in the end. Starting with the BB UI and customizing saves a lot of time and effort.

Even in gaming applications, or for applications where you're custom drawing all your components, you have better access to the BlackBerry graphics APIs and get better performance going the BlackBerry native app route. And you still have better detail about input events.

Finally there are some nice lifecycle things you can do with BlackBerry native apps, like pushing to the background, or auto-running on system startup that you can't do with MIDlets, which may be of interest depending on your application.

Also think about market - if you're planning on supporting BlackBerry right away, and then maybe other MIDP platforms down the road, it's usually a better plan to execute the best you can on your initial platform. There probably won't be much of a reason to port to MIDP later if you don't succeed on BlackBerry first.

Answer 5

Without knowing the scope of your application, meaning which devices you will target, another thing that you will need to take into consideration is the ever expanding differences in input for each BlackBerry model. Some devices, like the Curve and the Bold, are standard QWERTY pads where other devices, like the PEARL, have SureType pads. And then there's the Storm which supports both depending on the orientation of the screen. Also, the SureType pad needs to be used as a standard number pad if the user has it set that way. The native APIs have support for all of this where you won't have that luxury with standard MIDP.

Another tip when designing your user experience, I would get my hands on a few different BlackBerry models and try out some of the apps that come standard as there are a lot of shortcuts that users become accustomed to using that you might not even realize exist. For instance, the SPACE bar pages down. This is huge for reading docs, however I have a third party RSS feed reader that does not have this functionality and I always attempt to use it first before remembering that it doesn't exist in this app. That kind of small detail can make a huge difference to BlackBerry users.

Answer 6

J2ME is simple to develop. And, BlackBerry API has many feature also you can use restricted class with simple signing. BlackBerry sells their sign certificate and it is cheap. 20$. You can use this certificate to sign and use all restricted class. In J2ME, sometimes you must use more than one certificate, even you can not use all phone capabilities. So, my suggestion is, use BlackBerry native API and some J2ME Wrapper Codes. So that, you can code easly as J2ME and can use all capabilities of BlackBerry native API.