Question : Efficient J2me

Hi,

I'm struggling to find out details on packages and JAR files. I want to know the best way to use small amounts of RAM on a device. I believe MIDlet suites are the way to go but I'm not certain how to load specific parts of the source code only. Should there be a small program at startup which decides which MIDlet to use? Should packages be used or not - if so, do they load all classes in that package?!

Any help appreciated

Thanks

James.

Answer : Efficient J2me

Let's put your mind at rest regarding the packages first ;-)

Unless you use long package names in deeply nested structures, it will make practically no difference to your application size.  Since each MIDlet suite is self contained, you could just use a simple one-level package if you want, eg:

package tc45;

As far as the way you structure your MIDlets is concerned, I would suggest that you have a single MIDlet.  Keep the class that extends MIDlet quite small and carry out the check for the need to run the memory intensive code.  If this intensive code is kept in a separate class, it should not need to be loaded into memory until you actually create an instance of it. eg:

public class ShouldIStart extends MIDlet
{
    private IntensiveProcess intensiveProcess;

    // Standard methods, startApp(), pauseApp(), destroyApp()

    private void check()
    {
        if (processShouldRun)
        {
            intensiveProcess = new IntensiveProcess();
            intensiveProcess.execute();
        }
    }
}

public class IntensiveProcess
{
    public void execute()
    {
        // Do your stuff here.
    }
}

In this way, the IntensiveProcess class shouldn't be loaded into memory until you create the new instance.

There is no way for one MIDlet to start another.