cannot create class in system package

[DrChandra]

Hello,

I recently encountered this problem on 6110. I'm using MMAPI classes, but only if I successfully detect MMAPI on runtime, by testing system properties ("video.snapshot.encodings" and "microedition.media.version").

I tried it on several s60 phones and on 3120, works ok. But on 6110 it throws a "cannot create class in system package" error even though the code will never execute. I suspect I will encouter this on other phones as well.

Is there a workaround to this problem? Note that this is not a problem of runtime detection of optional packages; This is a problem of having an optional package class appear SOMEWHERE in the code, on the phone which does not support it.

Thanks!

[wang_shui]

Hi Chandra,

It can be due to that u may be using some other api which is not supported by 6110. this api may have been supported in 3120. So please check all the apis u r using in ur application.

Wang

[juarezjunior]

Hi DrChandra,

Are you sure you're talking about Nokia 6110? AFAIK it doesn't even support JME, so it won't support MMAPI as well. I cannot figure out how you deployed MIDlets on it...

Nokia 6110 - http://europe.nokia.com/nokia/0,8764,3277,00.html

Are you talking about Nokia 6111 instead of 6110?

BR,

Juarez Junior

[DrChandra]

Hi Chandra,

It can be due to that u may be using some other api which is not supported by 6110. this api may have been supported in 3120. So please check all the apis u r using in ur application.

Wang

Hi Wang,

I'm only using MMAPI optional package. I'm quite sure it's the cause of my problem, because when I comment out the call to api specific classes, the midlet works. (Even though the call would never happen in the first place).

[DrChandra]

Hi DrChandra,

Are you sure you're talking about Nokia 6110? AFAIK it doesn't even support JME, so it won't support MMAPI as well. I cannot figure out how you deployed MIDlets on it...

Nokia 6110 - http://europe.nokia.com/nokia/0,8764,3277,00.html

Are you talking about Nokia 6111 instead of 6110?

BR,

Juarez Junior

Hi Juarez,

You're right - it's not the 6110, it's 6610. It was a typo. Thanks for pointing it out

[traud]

There are some MIDP 1.0 devices from Nokia out there which use a wrong compiled Sun MIDP environment – never got fixed. When you are using JSRs conditionally, have a look at chapter 8.1 of the (forth-coming) JSR-248. It gives you good guidance, how to do this the right way. Good reading material anyway, as it contains a lot of knowledge about MIDP of today.

However, I am not sure if it fixes your case. Faced similar, however, I can not recall, if a appropriate strategy solved it.

[DrChandra]

Traud,

Yes, the strategy worked! The midlet loads successfully now on 6610.
Many thanks! It's a great reading material.

Cheers

[juarezjunior]

Hi DrChandra,

Could you please clarify how you solved your problem? Thanks!

BR,

Juarez Junior

[traud]

Have a look at that JSR-248 chapter 8.1. It is quite precise and contains an example, too.

[DrChandra]

As outlined in chapter 8.1 of JSR-248, I had to isolate the references to non-present APIs from the main body of the application. It is done by providing the interface to the class which is referencing the missing API. That class is instantiated using Class.forName() and Class.newInstance(). The application, after checking system properties to determine the existence of the API, references only the defined interface.

It is all explained in the JSR 248 with an example.

[juarezjunior]

Ok Traud and DrChandra,

Thanks a lot! I'll read the spec as required...

BR,

Juarez Junior