JSR 293: LBS Goes Social

[kevinauthor]

I just posted a video conversation I had with Carl Snellman, Sr. JME Engineer, Nokia; Steven Si, Global Lead Technical Consulting, NAVTEQ Network for Developers; and Matt Gross, General Manager, WHERE Developer Programs. They'll be returning to this thread to answer questions.

[csnellman]

Hey everyone,

My name is Carl Snellman, and I'm one of the members in the Expert Group defining the new JSR293 Location API 2.0. If you have any questions regarding the API, eg. what's new in the API, or just wanna chat about LBS in general, please dont hesitate to reply to this thread!

The latest API spec is available at http://www.jcp.org/en/jsr/detail?id=293 (although there has been minor changes after the January)

Carl

[kevin_s2f]

I'm one of the members in the Expert Group defining the new JSR293 Location API 2.0.

Anybody headed to Java One should check out the session Get on the Map Thursday, May 8, from 10:50 - 11:50. Jaana Majakangas and Carl will be talking about JSR 179 and 293.

[lbsuser]

Hi Carl,

I read through the Location API 2.0 JSR293 Version 0.16, in page 116 it writes "This specification defines client interfaces that applications can use to access location based services provided by the terminal implementation. This specification does not define a mechanism to include dynamic service provider implementations to the device implementations. They are out of scope for JSR 293. More information about service provider
implementations and their installation can be found from appendix E." But there isn't a appendix E through the specification, is there any place to find it? and are there some examples about the mechanism of how to implement the dynamic service provider?

Thanks

Hey everyone,

My name is Carl Snellman, and I'm one of the members in the Expert Group defining the new JSR293 Location API 2.0. If you have any questions regarding the API, eg. what's new in the API, or just wanna chat about LBS in general, please dont hesitate to reply to this thread!

The latest API spec is available at http://www.jcp.org/en/jsr/detail?id=293 (although there has been minor changes after the January)

Carl

[csnellman]

Hey,

Sorry that the appendix was missing from that version. I took a look on the latest version (0.18) and here's the text for that section:
Appendix 4. Service provider implementation
notes
This specification defines client interfaces that applications can use to access location based services provided by the
terminal implementation. This specification does not define a mechanism to include dynamic service provider
implementations to the terminal implementations. They are out of scope for JSR 293.
Dynamic service provider implementation
In order to be able to install service provider implementation to the terminal after it has been shipped, the terminal platform
must support some mechanism for that. This means that the platform must define an interface that allows the service
provider implementations register themselves to the JSR 293 implementation.
When the terminal platform has defined the service extension mechanism, the JSR 293 service provider implements that
interface. The service implementation is downloaded to the terminal via normal provisioning mechanisms. Once installed
the service implementation is integrated as part of the already existing JSR 293 implementation by the terminal platform
and the service is listed as one of the service through JSR 293 APIs.

So in other words, we cannot mandate any mechanism to dynamically add new providers to the devices; it is solely up to the manufacturer to provide the mechanism, if any, for example using OSGi. However, in case the manufacturer chooses to put in an implementation to access some standard services (for example, services asseccible using OpenLS or Web Map Services (WMS) protocols), then it could be possible to (by changing the url client points to) to access other services.

We will see how the implementations will be. I personally hope that implementations would be extensible some way, so that new services could be plugged in.

Hope this helped. Dont hesitate to send follow-up questions and comments!

Carl

Hi Carl,

I read through the Location API 2.0 JSR293 Version 0.16, in page 116 it writes "This specification defines client interfaces that applications can use to access location based services provided by the terminal implementation. This specification does not define a mechanism to include dynamic service provider implementations to the device implementations. They are out of scope for JSR 293. More information about service provider
implementations and their installation can be found from appendix E." But there isn't a appendix E through the specification, is there any place to find it? and are there some examples about the mechanism of how to implement the dynamic service provider?

Thanks

[lbsuser]

Thank you very much,Carl.

Hey,

Sorry that the appendix was missing from that version. I took a look on the latest version (0.18) and here's the text for that section:
Appendix 4. Service provider implementation
notes
This specification defines client interfaces that applications can use to access location based services provided by the
terminal implementation. This specification does not define a mechanism to include dynamic service provider
implementations to the terminal implementations. They are out of scope for JSR 293.
Dynamic service provider implementation
In order to be able to install service provider implementation to the terminal after it has been shipped, the terminal platform
must support some mechanism for that. This means that the platform must define an interface that allows the service
provider implementations register themselves to the JSR 293 implementation.
When the terminal platform has defined the service extension mechanism, the JSR 293 service provider implements that
interface. The service implementation is downloaded to the terminal via normal provisioning mechanisms. Once installed
the service implementation is integrated as part of the already existing JSR 293 implementation by the terminal platform
and the service is listed as one of the service through JSR 293 APIs.

So in other words, we cannot mandate any mechanism to dynamically add new providers to the devices; it is solely up to the manufacturer to provide the mechanism, if any, for example using OSGi. However, in case the manufacturer chooses to put in an implementation to access some standard services (for example, services asseccible using OpenLS or Web Map Services (WMS) protocols), then it could be possible to (by changing the url client points to) to access other services.

We will see how the implementations will be. I personally hope that implementations would be extensible some way, so that new services could be plugged in.

Hope this helped. Dont hesitate to send follow-up questions and comments!

Carl

[kevin_s2f]

Hi Everybody, Carl Snellman and Jaana Majakangas had a great session yesterday talking about JSR 179 and JSR 293. I hope some of you were able to attend the session. For those who were not able to join, they are both online now.

Good Morning Carl and Jaana.

[csnellman]

Hey all,

and welcome to the session! Feel free to bomb us with the hardest questions you have

Carl

Hi Everybody, Carl Snellman and Jaana Majakangas had a great session yesterday talking about JSR 179 and JSR 293. I hope some of you were able to attend the session. For those who were not able to join, they are both online now.

Good Morning Carl and Jaana.

[csnellman]

Hey all,

So yesterday I gave a talk at JavaOne2008 about LBS and new JSR 293 Location API 2.0. Thanks for everyone who participated, it was very nice to see so much interest (a full room) in this topic!

I showed a bunch of demos during the presentation, and I promised to post them all online. I'm just in process of posting them into a wiki page, so I will reply soon to this with the link (unfortunately this tool does not allow attaching files)

The first package contains all demo source code. The second package contains the latest specification, v.0.18. Please take a look and post all commments you have about the demos on this thread, and the comments about the specification to Expert Group's mailing list, jsr-293-comments@jcp.org

[kevin_s2f]

During your session, one of the people from the audience asked about criteria priorities that are new in JSR 293. Can you explain a little bit about that?

[kevin_s2f]

Carl, your demo code showed how to exchange landmarks over SMS using the new Landmark Exchange Format. That was cool. You also discussed a port handler to make that work. Can you talk about that a little?

[kevin_s2f]

demo code showed how to exchange landmarks over SMS using the new Landmark Exchange Format.

The full source code will be posted to the FN Wiki soon. Watch this thread for the URL to the article.

[jmajakan]

The problem with the criteria definitions in JSR 179 is that it is not easy to distinguish between different location providers. The differences for example for provider accuracies are minimal so the application developer does not know what is the location provider based on the criteria. In some cases this is OK, but there are use cases when you need to be able to select a certain location provider.

So in JSR 293 we added priorities for the criterion so that an application is able to set the different criterion into importance order and the location provider selection is done based on that order.
Another new feature in JSR 293 on this area is that now there is a way to get an instance of the LocationProvider class based on preferred location method. And the preference is defined with the MTE_*, MTY_* and MTA_* constanst in Location class.

During your session, one of the people from the audience asked about criteria priorities that are new in JSR 293. Can you explain a little bit about that?

[kevin_s2f]

The differences for example for provider accuracies are minimal so the application developer does not know what is the location provider based on the criteria.

So I can select the criteria and have a service provider selected for me. Can I directly select a service provider myself?

[kevin_s2f]

Carl, your demo code showed how to exchange landmarks over SMS using the new Landmark Exchange Format. That was cool. You also discussed a port handler to make that work. Can you talk about that a little?

The code also showed how to use the new APIs to draw maps with just a few lines of code. How did you do that?