Blackberry - LocationProvider.getLocation() hangs on

Question

I wrote a very simple application that asks the LocationProvider for a location and prints it to System.out. This works great in the simulator. However, when I run it on my blackberry device, the call to getLocation seems to hang indefinitely. I am running the code in a separate thread that simply gets a provider and asks for the location. I tried it with null Criteria (which should give me the defaults right?) as well as a Criteria that should provide Assist then Autonomous. I've included my code below. When I run this on my device it hangs on the call to getLocation.Here is my code below..plzz tell what i might be doing wrong...

public void getLocation() {
    Thread t = new Thread(new Runnable() {
     private double lat;
     private double lon;
     public void run() {
      Criteria cr = new Criteria();
      cr.setHorizontalAccuracy(Criteria.NO_REQUIREMENT);
      cr.setVerticalAccuracy(Criteria.NO_REQUIREMENT);
      cr.setCostAllowed(false);
      cr.setPreferredPowerConsumption(Criteria.NO_REQUIREMENT);
      cr.setPreferredResponseTime(1000);
      LocationProvider lp = null;
      try {
       lp = LocationProvider.getInstance(cr);
      } catch (LocationException e) {
      // System.out.println("*****************Exception" + e);
      }
      Coordinates c = null;
      if (lp == null) {
       UiApplication.getUiApplication().invokeLater(
        new Runnable() {
        public void run() {
         Dialog.alert("GPS not supported!");
         return;
        }
        });
      } else {
       // System.out.println("OK");
       switch (lp.getState()) {
       case LocationProvider.AVAILABLE:
       // System.out.println("Provider is AVAILABLE");
         Location l = null;
         try {
         l = lp.getLocation(-1);
        } catch (LocationException e) {
        // System.out.println("***Location Exception caught "
        // + e);
        } catch (InterruptedException e) {
        // System.out.println("***Interrupted Exception aught:"
        // + e);
        } catch (Exception e) {
        // System.out.println("***Exception caught :"
        // ;+ e);
        }
         if (l != null && l.isValid()) {
         c = l.getQualifiedCoordinates();
        }
        if (c != null) {
          lat = c.getLatitude();
         lon = c.getLongitude();
         System.out.println(lat + "  -  " + lon);
        }
       }
      }
     }
    });
    t.start();
}

Answer 1

try to:

• check if GPS on device is turned on
• check if your device and carrier have available GPS mode you are using (here)
• if your carrier is Verizone, check for Verizon GPSSettings signing requirement
• reset LocationProvider (desribed in Best practices for designing GPS applications for BlackBerry smartphones operating on CDMA networks)

---

Talking about hanging threads,

locationProvider.getLocation(-1)

hangs because if you use -1, there will be no timeout. Try this:

 int timeout = 120;
 try {
  location = provider.getLocation(timeout);
 } catch (LocationException e) {
  System.out.println("Location timeout");
 } catch (InterruptedException e) {
  System.out.println("InterruptedException"+e.getMessage());
 }

---

Also, if youre using System.out.println(text) in simulator, on device it would be better to

 getApplication().invokeLater(new Runnable(){public void run() {
      screen.add(new LabelField(text));   
     }});

or

 getApplication().invokeLater(new Runnable(){public void run() {
  Dialog.inform(text);   
 }});