JME Hello World

[paul wheaton]

Right now I'm trying to figure out how to get a java "hello world" running on this "Windows Mobile 5.0".

Any suggestions on a web page that might spell this out?

[Tim Holloway]

Have you done a google for "J2ME Hello World". Should take you there.

For the sordid details on Windows Mobile, see my reply to your post on same. Assuming that the JavaRanch server doesn't keep overloading.

[paul wheaton]

Google and I have been developing a deep relationship over the last 24 hours all about JME.

The stuff I've come up with so far seems to involve downloading a bunch of Micro$oft tools and cygwin. I can't help but think it has to be simpler than that.

[Tim Holloway]

Nonononoono!!!

Microsoft, Cygwin, et al need not apply. You should be able to do stock J2ME with just the developer's kit from java.sun.com - it even includes an emulator with plugins for popular feature sets.

Some device vendors do provide their own version of the J2ME developer system, and, alas, some of them are packaged as Windows apps, but the general-purpose one from Sun has no such limitations.

They also have some tutorials you may find useful. Last time I looked, there was a jump-off point for J2ME on the http://java.sun.com home page.
[ January 11, 2008: Message edited by: Tim Holloway ]

[Nicholas Jordan]

Originally posted by paul wheaton:
Google and I have been developing a deep relationship over the last 24 hours all about JME.

The stuff I've come up with so far seems to involve downloading a bunch of Micro$oft tools and cygwin. I can't help but think it has to be simpler than that.

[deleted noise, left relevant link - GDB]

See: J2ME MIDP and WAP Complementary Technologies
[ January 14, 2008: Message edited by: Gregg Bolinger ]

[paul wheaton]

The project of today cannot be done with WAP - there will be no net connection.

But there is another project I will be fiddling with in a few days that requires WAP.

....

The problem of the moment is that I cannot get my "Hello World" app to run.

There are two java files. The first is Moo.java:

    
package org.coastal.moo;
 
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
 
public class Moo extends MIDlet implements CommandListener
{
 
    private MooCanvas canvas;
 
    private Command exitCommand = new Command("exit", Command.EXIT, 99);
    private Command toggleCommand = new Command("toggle", Command.SCREEN, 1);
 
    public Moo()
    {
        canvas = new MooCanvas();
        canvas.addCommand(exitCommand);
        canvas.addCommand(toggleCommand);
        canvas.setCommandListener(this);
    }
 
    public void startApp() throws MIDletStateChangeException
    {
        Display.getDisplay(this).setCurrent(canvas);
        canvas.repaint();
    }
 
    public void destroyApp(boolean unconditional)
    {
    }
 
    public void pauseApp()
    {
    }
 
    public void commandAction(Command command, Displayable s)
    {
        if (command == toggleCommand)
        {
            canvas.toggle();
        }
        else if (command == exitCommand)
        {
            destroyApp(false);
            notifyDestroyed();
        }
    }
 
}
 

The second is MooCanvas.java

 
package org.coastal.moo;
 
import javax.microedition.lcdui.*;
 
public class MooCanvas extends Canvas
{
 
    private boolean toggle = true;
 
    void toggle()
    {
        toggle = !toggle;
        repaint();
    }
 
    public void paint(Graphics g)
    {
        int width = getWidth();
        int height = getHeight();
        g.setColor(0xffffff);
        g.fillRect(0, 0, width, height);
        String s = toggle ? "moo" : "mooooooo";
        Font font = g.getFont();
        int y = (height - font.getHeight()) / 2;
        int x = (width - font.stringWidth(s)) / 2;
        g.setColor(255, 0, 0);
        g.setFont(font);
        g.drawString(s, x, y, g.TOP | g.LEFT);
    }
 
}
  

Here is my ant script

    
<?xml version='1.0'?>
<project name='moo' default='build' basedir='.'>
 
    <property name="wtk.home" value="c:\WTK2.5.1"/>
    <taskdef resource="antenna.properties"/>
 
    <target name="build">
        <delete includeEmptyDirs='true' dir='build'/>
        <mkdir dir="build"/>
        <mkdir dir="build/classes"/>
        <wtkjad jadfile="moo.jad" jarfile="moo.jar" name="moo" vendor="Coastal Environmental Systems" version="0.0.1">
            <midlet name="moo" class="org.coastal.moo.Moo"/>
        </wtkjad>
        <wtkbuild srcdir="src/java" destdir="build/classes" preverify="false"/>
        <wtkpackage jarfile="moo.jar" jadfile="moo.jad" obfuscate="false" preverify="false">
            <fileset dir="build/classes"/>
        </wtkpackage>
    </target>
 
</project>
 

here is the resulting jad file:

    
 
MIDlet-Jar-URL: moo.jar
MIDlet-Jar-Size: 2597
MIDlet-Name: moo
MIDlet-Vendor: Coastal Environmental Systems
MIDlet-Version: 0.0.1
MIDlet-1: moo, , org.coastal.moo.Moo

When I run, I get the following:

    
Running with storage root temp.DefaultColorPhone2
Running with locale: English_United States.1252
Running in the identified_third_party security domain
Error verifying method org/coastal/moo/Moo commandAction(Ljavax/microedition/lcdui/Command;Ljavax/microedition/lcdui/Displayable :wink: V
Approximate bytecode offset 5: Inconsistent or missing stackmap at target
Method............: 10232ee4 'com/sun/midp/midlet/MIDletState.createMIDlet (static)' 
Stack Chunk.......: 22700ac
Frame Pointer.....: 2270104
Current IP........: 10339477 = 1033945a + offset 29
Previous Frame....: 22700cc
Previous IP.......: 103cd1c1 (offset 22)
Frame size........: 7 (1 arguments, 6 local variables)
Argument[0].......: 22708c0
Local[1]..........: 0
Local[2]..........: 23efca4
Local[3]..........: 227fdd0
Local[4]..........: 23efcb8
Local[5]..........: 10274980
Local[6]..........: 23efc84
Operand[1]........: 246f7fc
 
Method............: 10295734 'com/sun/midp/midlet/Selector.run (virtual)' 
Stack Chunk.......: 22700ac
Frame Pointer.....: 22700cc
Current IP........: 103cd1c1 = 103cd1ab + offset 22
Previous Frame....: 0
Previous IP.......: 1
Frame size........: 6 (1 arguments, 5 local variables)
Argument[0].......: 2270a50
Local[1]..........: 227feac
Local[2]..........: 22708c0
Local[3]..........: 0
Local[4]..........: 0
Local[5]..........: 0
Operand[1]........: 227feac
 
VM status:
Instruction pointer.: 10339477 (offset within invoking method: 29)
Next instruction....: 0x4c
Frame pointer.......: 2270104
Local pointer.......: 22700e8
Stack size..........: 128; sp: 227011c; ranges: 22700b4-22702b4;
Contents of the current stack frame:
    22700e8: 22708c0 (lp)
    22700ec: 0
    22700f0: 23efca4
    22700f4: 227fdd0
    22700f8: 23efcb8
    22700fc: 10274980
    2270100: 23efc84
    2270104: 22700cc (fp)
    2270108: 103cd1c1
    227010c: 22700e4
    2270110: 10232ee4
    2270114: 22700ac
    2270118: 0 (end of frame)
    227011c: 246f7fc (sp)
Execution stack contains 108 items: 
2270a50  
227feac  
22708c0  
0  
0  
0  
0  
1  
23efc88  
10295734  
22700ac  
0  
227feac  
22708c0  
0  
23efca4  
227fdd0  
23efcb8  
10274980  
23efc84  
22700cc  
103cd1c1  
22700e4  
10232ee4  
22700ac  
0  
246f7fc  
 
Execution completed.
3386027 bytecodes executed
146 thread switches
ALERT: java/lang/VerifyError: org/coastal/moo/Moo.
1669 classes in the system (including system classes)
17683 dynamic objects allocated (533084 bytes)
2 garbage collections (456052 bytes collected)
Execution completed.
3386027 bytecodes executed
146 thread switches
1669 classes in the system (including system classes)
17683 dynamic objects allocated (533084 bytes)
2 garbage collections (456052 bytes collected)
 

[paul wheaton]

Well, I'm still stuck. I've poked a few things around and tried to figure this out ....

Anybody see anything I'm doing wrong?

[Tim Holloway]

Well, a quick Google indicates that forgetting to preverify might do this.

[Tim Holloway]

Oops, almost forgot. I think WAP is about done for. The device you've been describing almost certainly runs Pocket Internet Explorer. And while PIE isn't up to fancy Flash or JavaScript tricks, you do feed it HTML.

It's just HTML formatted for a 320x240 screen or thereabouts.

[paul wheaton]

Originally posted by Tim Holloway:
Well, a quick Google indicates that forgetting to preverify might do this.

That worked!

Well, preverify-ing worked. "quick Google" didn't.