Do you think that dynamic jar loading is possible ??

[gizyy]

Hi everyone,

I have a final thesis and it is nearly done but my mentor wanted me to research about dynamic jar loading as a last step. The requirement is ; we have a mobile application it has some modules like tourism or such things and after application get started, the user selects the module that he wants, so after selection, application must connect to server to download the jar then i have to load it dynamically. The application already connects to my server and the rest is downloading the code, i think that there will be no problem at this step but i dont think that i can use jar file such this way. Do you have any idea??

[grahamhughes]

You cannot download more code into your application after installation. An application cannot span multiple JARs. Also, you cannot convert a byte[] into a Class, as you can with J2SE (using a ClassLoader), because there are no ClassLoaders in CLDC.

You can use MIDlet.platformRequest(), with the URL to a JAD, to download and install another application. However, this will be a separate application, and sharing data between applications (in separate JARs) is not easy. You can (on MIDP-2.0 and later) share record stores (RMS) between applications, but this is subject to security restrictions, and on some devices it might require that your application be signed.

Graham.

[im2amit]

I have a final thesis and it is nearly done but my mentor wanted me to research about dynamic jar loading as a last step. The requirement is ; we have a mobile application it has some modules like tourism or such things and after application get started, the user selects the module that he wants, so after selection, application must connect to server to download the jar then i have to load it dynamically. The application already connects to my server and the rest is downloading the code, i think that there will be no problem at this step but i dont think that i can use jar file such this way. Do you have any idea??

You can have small start or setup application in the same name as your final project as version 0.5 (often called stub app). This application will let the user select the required options based on which you do a plaform request to the server and get the complete application OTA which updates this existing app on the device.

thanks,
~Amitabh

[gizyy]

You cannot download more code into your application after installation. An application cannot span multiple JARs. Also, you cannot convert a byte[] into a Class, as you can with J2SE (using a ClassLoader), because there are no ClassLoaders in CLDC.

You can use MIDlet.platformRequest(), with the URL to a JAD, to download and install another application. However, this will be a separate application, and sharing data between applications (in separate JARs) is not easy. You can (on MIDP-2.0 and later) share record stores (RMS) between applications, but this is subject to security restrictions, and on some devices it might require that your application be signed.

Graham.

I see, it seems impossible. Thank you very much.

[gizyy]

You can have small start or setup application in the same name as your final project as version 0.5 (often called stub app). This application will let the user select the required options based on which you do a plaform request to the server and get the complete application OTA which updates this existing app on the device.

thanks,
~Amitabh

Thank you for the idea but I think this is not the exact thing that my mentor wants. Thanks again.