My name is Alessandro La Rosa, and I'm a mobile developer from Rome, Italy.
Feel free to contact me at: info@jappit.com
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Leonardo Risuleo Biskero.org
I finally found some time to finish and publish the first release of a tiny library that allow to easily integrate Google Maps in every J2ME application: MidMaps.
You can read all the details, download the library together with sample code, and read the full JavaDocs here: MidMaps – J2ME Google Maps library.
When developing a Flash Lite, Web Runtime or Java ME application based on API Bridge, one of the things you know you’ll have to deal with is the Symbian packaging and signing process.
For single-person and small developer teams, the whole Symbian process could be a not suitable option. For this reason, I’ve looked for an alternative deployment approach that could bypass this process. The approach presented here is based on a delayed deploy model, meaning that the API Bridge engine is not deployed with your application, but in a successive moment: actually, it is deployed only when the application needs it.
How this can be achieved? Basically, there are 2 possible options to implement this model, and they’re based on:
If the target devices support Platform Services, the AppManager API can be used to retrieve the list of installed applications, and so to check if API Bridge is installed on the device itself.
The code below shows how this can be achieved by using JavaScript in a WRT widget. The same approach can be easily ported to ActionScript, and so used in a Flash Lite application.
var apiBridgeFound = false; var apiBridgeCheckError = null; var so = device.getServiceObject("Service.AppManager", "IAppManager"); var criteria = new Object(); criteria.Type = 'Application'; var result = so.IAppManager.GetList(criteria); if(result.ErrorCode == 0) { var iterator = result.ReturnValue; var application; while((application = iterator.getNext()) != undefined) { if(application.Uid == '0x20023710') { apiBridgeFound = true; break; } } } else { apiBridgeCheckError = result.ErrorMessage; }
The code works by checking the UID of all the installed applications, comparing them with the API Bridge UID (0×20023710). This code snipped defined 2 variables, that can be used to check for API Bridge availability:
So, once these 2 variable have been set, the application can perform the most appropriate operation, based on the AppManager call result. The code snippet below shows a possible implementation:
if(apiBridgeCheckError != null) { alert("There was an error! " + apiBridgeCheckError); } else if(!apiBridgeFound) { if(confirm("You have to install API Bridge to continue, press OK to download it")) { widget.openURL('http://www.yourserver.com/APIBridge_v1_1.sis'); } } else { alert("API Bridge is already installed on the device!"); }
And below you can see this code running on a Nokia 5800 XpressMusic:
Since the API Bridge engine works as a local HTTP server running on the mobile phone, the other possible approach is to make an HTTP request, and to check if any response from API Bridge comes.
Note: this approach works by using the API Bridge default port (9080). There are no guarantees that this port number is fixed, and that it will not be changed in future API Bridge releases. For this reason, my advice would be to use this second approach only when Platform Services are not available.
The code below shows how to make a request to the local API Bridge HTTP server, and how to check if it’s running or not: if it is running, the response status of the XMLHttpRequest object has to be different than zero.
function pollApiBridgeServer(_callback) { var request = new XMLHttpRequest(); request.open("GET", "http://127.0.0.1:9080", true ); request.send(null); request.onreadystatechange = function() { if( request.readyState == 4) { if(request.status != 0) { _callback(true); } else { _callback(false); } } } }
The approach described here can be used also when using API Bridge from other languages, as Flash Lite or Java ME. Anyway, when working with Flash Lite, in the scenario where API Bridge is not yet installed, you will incur in the typical (and horrible) error popups, that will inform you (and so the user) that the network call failed.
How to use the code above? First, define a callback:
function pollApiBridgeCallback(apiBridgeInstalled) { if(apiBridgeInstalled) { alert("API Bridge is already installed on the device"); } else { if(confirm("You have to install API Bridge to continue, press OK to download it")) { widget.openURL('http://www.yourserver.com/APIBridge_v1_1.sis'); } } }
Then, just call the pollApiBridgeServer() method by passing a reference to this callback:
pollApiBridgeServer(pollApiBridgeCallback);
Using one of the two approaches discussed above as some important advantages over the standard API Bridge deployment mechanism:
On the other side, these approaches have the main drawback on the user-experience side, since your users could be asked to download and install an additional component when they start to use your application. Anyway, this event will happen only once at most, so it could be considered reasonable in most scenarios.
If you’re developing applications for Nokia devices, and more specifically Web Runtime, Flash Lite or Java ME applications, you probably already had to deal with the platform limitations, and with the tools and libraries that allow to go beyond these limitations by adding more capabilities.
Basically, when you want to extend the functionalities of a WRT widget or a Flash Lite application, you have two options:
Both of them provide a set of tools and libraries that, added to your applications, allow them to access more functionalities than the ones that each technology naively supports.
So, which approach is the best one? It’s not easy to give a unique answer to this question, so let’s go into details.
The Platform Services library is available from more time, and there’s a well established set of resources and code examples that will help you to quickly get your functionalities ready and running.The primary source of information is Forum Nokia Library, that has a detailed references of APIs and useful sample code. Then, also Forum Nokia Wiki provides an extensive set of examples that cover all the possible usage scenarios. Even if there is some little parts where this information could be improved, you shouldn’t get much in trouble when using Platform Services in your application.
API Bridge is a fresher technology, released on November 2009, and so it’s harder to find complete documentation and usage examples. Anyway, Forum Nokia released a set of libraries for various platforms (Flash Lite, Web Runtime and Java ME) that will definitely help in starting to use API Bridge.
Platform Services are fully supported starting from S60 5th edition devices, but are also compatible with a subset of S60 3rd edition Feature Pack 2 devices: the full list of supported devices is available here: Web Runtime 1.1 compatible devices. This means that you can use them only on the touch screen Nokia devices.
On the other side, API Bridge can work on all devices starting from S60 3rd edition Feature Pack 1 onwards, so meaning:
Current Platform Services (version 1.0) allow to access a wide set of features:
It is currently available also a beta release of Platform Services 2.0, that adds to this features’ set also the access to the device camera.
API Bridge, instead, has a more limited set of functionalities, currently including:
Platform Services are currently available for Flash Lite and Web Runtime applications.
API Bridge libraries have been released for Flash Lite, Web Runtime and Java ME. Generally speaking, the API Bridge engine, working as a local HTTP server running on the device, is accessible from all technologies.
The current implementation of Platform Services and API Bridge don’t allow to decide which approach is the best one, and there is no need to do it anyway. Right now, if you’re working in Flash Lite or Web Runtime, and as long as your set of target devices support them, you can benefit of both technologies, including the two libraries in your application.
Talking about future perspectives of both approaches, we can see both of them evolving in more mature products.
Platform Services 2.0 is already available as a beta release, so you can already start experimenting with the new APIs and features, including the access to the device camera. On the other side, API Bridge promises to allow everyone to create custom plugins, through the ECOM interface, as reported on Forum Nokia Blogs.
Concluding, Platform Services, with the already mature and features-rich library, surely represents a simpler approach for developers who don’t want to deal with Symbian building and packaging, while API Bridge, with its plugin architecture becoming mature and open to developers, could definitely end up to be the best ally to allow widgets and Flash Lite apps access more and more features.
>On the other side, API Bridge promises to allow everyone to create custom plugins, through the ECOM interface, as reported on Forum Nokia Blogs.
They just release APIBridge Plug-in API: http://wiki.forum.nokia.com/index.php/APIBridge_Plug-in_API
Hi Trufanov,
you’re right! Just noticed the same thing
This week’s featured article on Forum Nokia Wiki, written by Jarmlaht, does a good job explaining how to use USB cable connections in Java ME, covering a topic where references and sample code are really few.
This article updates the existing Forum Nokia document MIDP: Using Cable Connection In Nokia Devices. The document explains how to use CommConnection over cable in Nokia devices. There are differences in devices and their port numbers, and also on PC side. In practice using USB connection between PC and mobile device might need some testing.
The Series 40 5th Edition SDK, Feature Pack 1 Lite is now available for download on Forum Nokia.
For more infos about Series 40 5th edition Feature Pack 1 Lite, you can check out Forum Nokia technology spotlight.
A full list of devices is also available here.
I’m working on the next Gcal version, and would be interested to know which features Gcal users would like to see most in the very next release. If your most wished feature is not listed below, just add it as a comment to this post!
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Thank you for these initial votes! It seems that syncing is by far the most desired feature on Gcal
In some way this is something I didn’t expect, for 2 reasons:
* there are some syncing solutions, implemented in Java ME, that already do a good job of syncing the local calendar with Google Calendar
* Gcal is some way should “substitute” the need of syncing the 2 calendar, since it gives you access to Google Calendar in every moment
Probably, having Gcal working also offline could be an intermediate solution that could fit the same needs, what do you think about it?
native blackberry support.
Hi aston,
thank you for your feedback. BlackBerry support is one of the poll’s options, so let’s vote it to push onto the next release
Pat is discussing. 
aston, and
Pat 4:16 am on March 1, 2010 Permalink
Hi Alessandro , I’m trying to understand how to package/install a custom API bridge with a J2ME app. A specific post about that would be great. Thanks.