J2ME gurus, please help a newbie.
Hi!
My task is to develop an application for a Palm Pilot device, which will communicate with the server and read and update data in a relational database (via EJBs). I am new to programming with Java 2 Micro Edition, so I've got some questions.
1. Is it true, that MIDlets are completely isolated from the outside world, i.e. it is not possible to post data from the hanheld device to the server, or to read data from the server into the handheld device?
2. What about writing native methods for j2me apps? Can I implement all the necessary communications functionality in native methods using the C SDK?
3. I downloaded the MIDP.prc and the examples into my Palm OS Emulator. The emulator settings are: Palm OS version = 3.5.1 and total memory size = 4 Mb. The java vm starts but running the examples causes very many errors of the type: "An application ... referenced memory location ..." and so on. What's the matter? Is something wrong with the emulator?
4. I come from outside US, therefore I can't dowload the file j2me_cldc-1_0_2-fcs-src-b12-winunix-5_Jun_2001.zip. Can anybody send it to me?
Thanks in advance. Zhenya.
[1180 byte] By [
zzhtan] at [2007-9-26 6:00:49]
[zzhtan],
> Hi!
> My task is to develop an application for a Palm Pilot
> device, which will communicate with the server and
> read and update data in a relational database (via
> EJBs). I am new to programming with Java 2 Micro
> Edition, so I've got some questions.
>
> 1. Is it true, that MIDlets are completely isolated
> from the outside world, i.e. it is not possible to
> post data from the hanheld device to the server, or to
> read data from the server into the handheld device?
Not really. The CLDC/MIDP specification states that any MIDP compliant device must provide the HTTP networking capabilities. A HTTP connection can be made over any underlying protocol implemented by the device.
> 2. What about writing native methods for j2me apps?
> Can I implement all the necessary communications
> functionality in native methods using the C SDK?
CLDC/MIDP does not support JNI.
> 3. I downloaded the MIDP.prc and the examples into my
> Palm OS Emulator. The emulator settings are: Palm OS
> version = 3.5.1 and total memory size = 4 Mb. The java
> vm starts but running the examples causes very many
> errors of the type: "An application ... referenced
> memory location ..." and so on. What's the matter? Is
> something wrong with the emulator?
>
> 4. I come from outside US, therefore I can't dowload
> the file
> j2me_cldc-1_0_2-fcs-src-b12-winunix-5_Jun_2001.zip.
> Can anybody send it to me?
As long as you are a member of SDC (SUN Developer Connection), you should be able to access http://java.sun.com and drill through the URL links to find the CLDC 1.0 reference implementation packages download it over the Internet. We don't really understand your question here - are you having issues with downloading from the http://java.sun.com website?
> Thanks in advance. Zhenya.
HTH.
Allen Lai
Developer Technical Support
SUN Microsystems
http://www.sun.com/developers/support/
> [zzhtan],
>
> > Hi!
> > My task is to develop an application for a Palm
> Pilot
> > device, which will communicate with the server and
> > read and update data in a relational database (via
> > EJBs). I am new to programming with Java 2 Micro
> > Edition, so I've got some questions.
> >
> > 1. Is it true, that MIDlets are completely isolated
> > from the outside world, i.e. it is not possible to
> > post data from the hanheld device to the server, or
> to
> > read data from the server into the handheld device?
> Not really. The CLDC/MIDP specification states that
> any MIDP compliant device must provide the HTTP
> networking capabilities. A HTTP connection can be made
> over any underlying protocol implemented by the
> device.
>
> > 2. What about writing native methods for j2me apps?
> > Can I implement all the necessary communications
> > functionality in native methods using the C SDK?
> CLDC/MIDP does not support JNI.
>
> > 3. I downloaded the MIDP.prc and the examples into
> my
> > Palm OS Emulator. The emulator settings are: Palm
> OS
> > version = 3.5.1 and total memory size = 4 Mb. The
> java
> > vm starts but running the examples causes very many
> > errors of the type: "An application ... referenced
> > memory location ..." and so on. What's the matter?
> Is
> > something wrong with the emulator?
> >
> > 4. I come from outside US, therefore I can't
> dowload
> > the file
> > j2me_cldc-1_0_2-fcs-src-b12-winunix-5_Jun_2001.zip.
> > Can anybody send it to me?
> As long as you are a member of SDC (SUN Developer
> Connection), you should be able to access
> http://java.sun.com and drill through the URL links to
> find the CLDC 1.0 reference implementation packages
> download it over the Internet. We don't really
> understand your question here - are you having issues
> with downloading from the http://java.sun.com
> website?
>
> > Thanks in advance. Zhenya.
>
> HTH.
>
> Allen Lai
> Developer Technical Support
> SUN Microsystems
> http://www.sun.com/developers/support/
I get the following error message from the Sun download center when I try to download the file:
"This product cannot be exported to your address.Please see the Download Center FAQ for more information."
