Daniel Rocha's Forum Nokia Blog

Which technology should I use for development? Round 1: Java

Tue, 27 May 2008 18:29:05 +0000

If I had just made a dollar each time I heard this question... *sigh*.

With the availability of so many different development technologies in Nokia's platforms today, sometimes is hard to decide which of them we should use to build our application, isn't it? There's Java, Symbian C++, Open C, Flash Lite, WidSets, WRT Widgets, Python, and the list is still growing.

This is good news for developers, since not everybody has the same technical background nor is developing the same kinds of applications; this means at least one of the technologies will fit our experience and purpose like a glove, and we are going to use it. On the other side, this may confuse newcomers to the wonderful but fragmented mobile software world. Usually it goes like this:

Question: "I want to write an application that opens a file and sends it out to a web server. What should I use to create it?"
Answer 1: "Java ME, FileConnection API"
Answer 2: "Don't bother, use C++ or you will get a lot of security prompts."
Answer 3: "Why use C++ when you can do the same with Python? C++ is way too hard!"
Answer 4: "Python does not run on S40, use Java."
Answer 5: "Do you really need all that jazz? Why don't you go with Flash Lite and use server-based persistence? Your application will look great!"
Answer 6: "Flash Lite is too fragmented. Use Java, but beware of the MIDlet signing issues or your app's user experience will be crap!"

Go check the Discussion Boards. It is crowded with examples of conversations like the one above. Having answered this question so many times before, I decided to summarize my answers in this blog, in the hopes of helping developers decide what use from the growing technology options pool offered in mobile devices these days. Please keep in mind that the following are my opinions on the subject; yours may differ and even prove mine wrong, but that's the beauty of interacting with people within a community. As the number of technologies it too big for a single post, I will continue my analysis in the upcoming posts. I will start off with the most popular mobile developmentp platform, Java ME.

Technology: Java

Good for:

Productivity applications - Examples: sports trackers, expense control apps, Personal Information Management (calendar, phonebook, etc.).
Games - Both casual and complex.
Enterprise applications - These don't require fancy user interfaces. Using LCDUI and the standard packages can go a long way pretty fast.
Rapid prototyping and proof-of-concept applications.
Network applications - RSS readers, weather services, blogging applications, mobile versions of Web applications.
Creating truly portable apps

Why?

Java and its mobile version are very simple to use and learn - An experienced programmer, even coming from other C/C++-based languages, can get a pretty good working knowledge of how everything works in a matter of weeks and start producing applications quickly. This leads to faster time-to-market for Java ME apps.
Applications are generally portable between S60 and S40 platforms - Although there are some differences in implementation, supported packages, audio/video formats and so on, those are few in number and thus easier to work around. You don't need to entirely rewrite your application so it will run on N95 instead of 6131: a few runtime checks and versioning tools will be enough.
Game API combined with optional packages makes it a killer for game development
Straightforward network API makes it easy to communicate with web services - The GCF (Generic Connection Framework) is a simple and unified way of using the network on Java ME applications. Once you learn how to do one kind of connection, you will have learned them all.

Bad for:

Accessing device resources - Examples: SMS Inbox, file system, gallery, hardware.
Multimedia applications - Examples: Video streaming players, audio and video recorders, camera applications.
Performance-intensive applications - Scientific computing, image processors, video decoders, sound processors.

Why?

Java's functionalities depend on Java Community Process process: if there's no official, industry-standard API for what you want to do, you are out of luck. Example: accessing SMS inbox.
Mobile Media API implementation is (too) highly modular, a lot of runtime checks are needed. Also, most functionality is implemented on the native side and then made available to Java's virtual machine, such as the camera access. This may have a serious impact on performance.
Fine-grained control over video, audio and camera is generally not available. Although JSR 234 (Advanced Multimedia Supplements) tackles some of these issues, it still can't be compared to what's available on other technologies, and its device availability is still low.
Access to the file system is provided by FileConnection API, but it's somewhat restricted and requires the midlet to be signed, otherwise multiple security prompts will be displayed, taking your user to tears (believe me). The signing process itself costs money and has some bureaucracy, so be prepared.

As I said before, these are my opinions on the technologies. It does not mean that X is better than Z, and Z should be thrown into the dirt and kicked in the head, like XML in the funny The Parable of the Languages. If you get your requirements right, it's very likely that your question of "what to use" will answer itself. Need to access the Inbox? Down with Java. Need portability? Down with Python and C++. Fancy UI? Flash. Requirements management is a science, not an art, so when you get it right from the start, the development technology to use will pop up naturally.

Next time I will cover the darling of all Internet programmers, now getting much of the attention on S60 platform: Python.

See you!

Make your widgets and Flash Lite applications fly!

Mon, 24 Mar 2008 19:09:47 -0100

As I mentioned in my last post, I have been thinking a lot lately about how to extend applications that run on sandboxed environments, such as Java ME, Flash Lite and Widgets, using some powerful native technologies such as C++, Python and Mobile Web Server.

I did my research and turns out some people have already been thinking (and doing) this for a while now, so I wanted to share this with you, for a reason I will explain later:

- Our very own Sr. Technology Expert Petro Soininen has created a widget that's able to send text messages and read the SMS inbox of an S60 device, using a creative combination of Widgets, Python, PHP and the Mobile Web Server. Here's the link for the article with complete source code: http://wiki.forum.nokia.com/index.php/How_to_utilize_device_resources_from_a_WRT_widget

- Forum Nokia Champion Felipe Andrade and his company have been working for quite some time in the Flyer Framework, a server application written in Python for S60 whose goal is to provide enhanced native functions to Flash Lite applications. It looks pretty mature, and I wonder if it could be used with Widgets as well with some adjusts in connectivity (full HTTP vs XML sockets).

I mentioned these two ways of extending widgets and Flash Lite apps because of the Global Code Camp Contest. I figured that an application/widget with enhanced functionality has more room for being innovative and delight users in many different ways.

As nothing was mentioned in the contest rules, I asked the Forum Nokia team responsible for the competition whether applications produced with these extension methods would be valid or not. An the answer is that these turbo web widgets and Flash apps are allowed, so you have a lot more options to introduce cool features in your apps via sweet Python and PHP scripts.

So take a look at them both and make your widgets and Flash apps fly higher than ever!

Hurrah! Widgets! - and more

Thu, 20 Mar 2008 17:43:40 -0100

If you have been reading Forum Nokia web site regularly, you've probably noticed the big Win 15k Euros! posted on the main page since March 18th. If you click the link, you'll be redirected to the Forum Nokia Code Camp Competion we're hosting. It's all about you developing a winning Web Run-Time (WRT) or Flash Lite application and raking in a lot of nice prizes from Forum Nokia.

Registration has already begun, so come up with your bright idea for either platform and enter the competition!

If you have a concept but don't have a command in any of these technologies, a good idea would be to register for one of the Forum Nokia Regional Code Camps happening worldwide and get started with both WRT and Flash in nice hands-on workshops.

Yours truly will be probaly hosting a Flash Lite somewhere in April, stay tuned.

If you're more into widgets, you can also get started by checking out this article I wrote back in November 07. It covers everything you need to know to develop your first widget, including SDK and live testing with our Remote Device Access service:

Widgets on S60: Web Runtime

* * *

I have been thinking a lot about Python for S60, Mobile Web Server and how to extend Flash and Java applications using the former technologies. I wonder if it would be possible to extend Widgets as well, having a C++ or Python light web server running on the phone while a widget makes local XMLHttpRequest connections to this service, thus getting more native-related functionality. Mobile Web Server seems like a good candidate for this type of experimentation. I may give it a try soon. (evil laugh)