IllegalStateException BlackBerry - exception

Question

public class show extends MainScreen {
private String date1;
private long date1l;
private long date2l;
private LabelField curDate = new LabelField();
private LabelField toDate = new LabelField();
private LabelField diffe = new LabelField();
// private LabelField info;
// private LabelField empty;
// private InvokeBrowserHyperlinkField hello;
ButtonField activate = null;
ButtonField disactivate = null;
Timer timer;
Timer timer2;
public String date1s[];
int d, m, y;
int x = 1;
String day, hour, minute;
Date date = new Date();
Calendar calendar = Calendar.getInstance();;
SimpleDateFormat dateFormat = new SimpleDateFormat("dd MM yyyy HH mm");
public show() {
add(curDate);
add(toDate);
add(new SeparatorField());
add(diffe);
timer = new Timer();
timer.scheduleAtFixedRate(new TimerTick(), 0, 1000);
}
private class TimerTick extends TimerTask {
public void run() {
if (x != 0) {
date1l = date.getTime();
try {
date1 = dateFormat.format(calendar.getTime());
} catch (Exception e) {
e.printStackTrace();
}
Calendar cal = Calendar.getInstance();
cal.setTimeZone(TimeZone.getTimeZone("GMT+7:00"));
cal.set(Calendar.HOUR_OF_DAY, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.MONTH, 1);
cal.set(Calendar.DATE, 1);
cal.set(Calendar.YEAR, 2012);
date2l = cal.getTime().getTime();
date1s = StringUtilities.stringToWords(date1);
d = Integer.parseInt(date1s[0]);
m = Integer.parseInt(date1s[1]);
y = Integer.parseInt(date1s[2]);
display();
} else {
timer.cancel();
}
}
}
public void display() {
String monw = convertToWords(m);
curDate.setText("Current Date = " + d + " " + monw + " " + y + " "
+ date1s[3] + ":" + date1s[4]);
toDate.setText("To Date = 1 February 2012 00:00");
long diffms = date2l - date1l;
long ds = diffms / 1000;
long dm = ds / 60;
long dh = dm / 60;
long dd = dh / 24;
long q = dd;
long h = (ds - (dd * 24 * 60 * 60)) / (60 * 60);
long m = (ds - (dh * 60 * 60)) / 60;
diffe.setText("Remaining Time : \n" + Long.toString(q) + " day(s) "
+ Long.toString(h) + " hour(s) " + Long.toString(m)
+ " minute(s)");
day = Long.toString(q);
hour = Long.toString(h);
minute = Long.toString(m);
showMessage();
}
/*
* private void link() { empty = new LabelField("\n\n"); add(empty); hello =
* new InvokeBrowserHyperlinkField("Click here",
* "http://indri.dedicated-it.com/wordpress/?page_id=17"); add(hello); info
* = new LabelField("\n\nPress menu then choose \"Get Link\" to access");
* add(info); }
*/
void showMessage() {
activate = new ButtonField("Activate", FIELD_HCENTER) {
protected boolean navigationClick(int action, int time) {
if (activate.isFocus()) {
Dialog.alert("Started!!");
Start();
}
return true;
}
};
add(activate);
disactivate = new ButtonField("Disactivate", FIELD_HCENTER) {
protected boolean navigationClick(int action, int time) {
if (disactivate.isFocus()) {
Dialog.alert("Stopped!!");
timer2.cancel();
}
return true;
}
};
add(disactivate);
/*
* UiEngine ui = Ui.getUiEngine(); Screen screen = new
* Dialog(Dialog.D_OK, data, Dialog.OK,
* Bitmap.getPredefinedBitmap(Bitmap.EXCLAMATION),
* Manager.VERTICAL_SCROLL); ui.queueStatus(screen, 1, true);
*/
}
public void Start() {
timer2 = new Timer();
timer2.scheduleAtFixedRate(new TimerTick2(), 0, 6000);
}
private class TimerTick2 extends TimerTask {
public void run() {
UiApplication.getUiApplication().invokeLater(new Runnable() {
public void run() {
synchronized (Application.getEventLock()) {
UiEngine ui = Ui.getUiEngine();
Screen screen = new Dialog(Dialog.D_OK, "Hello!",
Dialog.OK,
Bitmap.getPredefinedBitmap(Bitmap.EXCLAMATION),
Manager.VERTICAL_SCROLL);
ui.pushGlobalScreen(screen, 1, UiEngine.GLOBAL_QUEUE);
}
}
});
}
}
private String convertToWords(int m) {
String w = "";
switch (m) {
case 1:
w = "January";
break;
case 2:
w = "February";
break;
case 3:
w = "March";
break;
case 4:
w = "April";
break;
case 5:
w = "May";
break;
case 6:
w = "June";
break;
case 7:
w = "July";
break;
case 8:
w = "August";
break;
case 9:
w = "September";
break;
case 10:
w = "October";
break;
case 11:
w = "November";
break;
case 12:
w = "December";
break;
}
return w;
}
public boolean onClose() {
UiApplication.getUiApplication().requestBackground();
return true;
}
}
What actually is JVM 104 IllegalStateException? This program is a countdown program, which counts the remaining time from today until February 1st. Also, I implement a timer function that appears even if the application is closed. Can u please help me locate the problem? Thank you

Answer 1

As Richard said, you are trying to update LabelField from another thread. Try the following code snippet:
synchronized (UiApplication.getEventLock()) {
labelField.setText();
}

Answer 2

Try this below code and change according to your requirement;
public class FirstScreen extends MainScreen implements FieldChangeListener
{
LabelField label;
Timer timer;
TimerTask timerTask;
int secs=0;
long start,end;
String startDate="2012-01-28",endDate="2012-01-29";
ButtonField startCountDown;
public FirstScreen()
{
createGUI();
}
private void createGUI()
{
startCountDown=new ButtonField("Start");
startCountDown.setChangeListener(this);
add(startCountDown);
}
public void fieldChanged(Field field, int context)
{
if(field==startCountDown)
{
start=System.currentTimeMillis();
//this is the current time milliseconds; if you want to use two different dates
//except current date then put the comment for "start=System.currentTimeMillis();" and
//remove comments for the below two lines;
//Date date=new Date(HttpDateParser.parse(startDate));
//start=date.getTime();
Date date=new Date(HttpDateParser.parse(endDate));
end=date.getTime();
int difference=(int)(end-start);
difference=difference/1000;//Now converted to seconds;
secs=difference;
Status.show("Seconds: "+secs,100);
callTheTimer();
}
}
public void callTheTimer()
{
label=new LabelField();
add(label);
timer=new Timer();
timerTask=new TimerTask()
{
public void run()
{
synchronized (UiApplication.getEventLock())
{
if(secs!=0)
{
label.setText(""+(secs--)+" secs");
}
else
{
timer.cancel();
UiApplication.getUiApplication().invokeLater(new Runnable()
{
public void run()
{
label.setText("");
Dialog.alert("Times Up");
}
});
}
}
}
};
timer.schedule(timerTask, 0, 1000);
}
protected boolean onSavePrompt()
{
return true;
}
public boolean onMenu(int instance)
{
return true;
}
public boolean onClose()
{
UiApplication.getUiApplication().requestBackground();
return super.onClose();
}
}
In this code I am taking taking two different dates and start the countdown by taking their difference(in seconds); See the comments in the code;