Static variables store values ​​from a previous run

Question

My j2me application call destroyApp()and notifyDestroyed()when it wants to be closed when I run it on a blackberry, in the second run the static variables will have the same values ​​as in the previous run.

Why don't they get the initial value? How can I make sure the application initializes static variables?

Answer 1

This discussion on the Blackberry support forums suggests that this is a known issue with the BlackBerry MIDlet - at least those using static push registries. The workarounds that they offer are either overriding the static variables in startApp, or getting rid of the static push.

This post is worth extensive quoting as there is a good code example and release analysis:

The simplest example I could come up with is this:

public class BasicMIDlet extends MIDlet {

    private static byte myByte = Byte.MIN_VALUE;

    public void startApp() {
        System.out.println("My byte: " + myByte);
        myByte = Byte.MAX_VALUE;
        notifyDestroyed();
    }

    public void pauseApp() {
    }

    public void destroyApp(boolean unconditional) {
    }


}

You expect myByte to output -128 every time the application starts, but this is my output:

--------------------------------------------------------

Starting BBTest
Started BBTest(159)
Foreground BBTest(157)
My byte: -128                          <------------
Foreground net_rim_bb_ribbon_app(83)
Exit BBTest(159)
Starting BBTest
Started BBTest(160)
Foreground BBTest(157)
My byte: 127                          <------------
Foreground net_rim_bb_ribbon_app(83)
Exit BBTest(160)
Starting BBTest
Started BBTest(161)
Foreground BBTest(157)
My byte: 127                          <------------
Foreground net_rim_bb_ribbon_app(83)
Exit BBTest(161)
--------------------------------------------------------

-, push, -128 . , , RIMlet, , push-, RIMlet . , : - , ( > 1000 )

Answer 2

, . , , , , - , null . , var : public static String State = null; ""; "" .

Answer 3

, " , ".

. destroyApp()/notifyDestroyed(), !

To save state for several runs, use RecordStore.