1. Import the required classes.

   import javax.microedition.location.*;

2. Create a class and a constructor.

   public class handleGPS
   {
      public handleGPS()
      {
      }
   }

3. Declare static fields in the class.

   static GPSThread gpsThread;
   static double latitude;
   static double longitude;

4. In the constructor, create and start a local thread.

   gpsThread = new GPSThread();
   gpsThread.start();

5. In the class, create a private class that extends Thread, and create a run() method.

   private class GPSThread extends Thread
   {
      public void run()
      {
      }
   }

6. In the run() method, create an instance of the Criteria class. Invoke setCostAllowed(false) to specify that the autonomous mode.

   Criteria myCriteria = new Criteria();
   myCriteria.setCostAllowed(false);

7. In the run() method, create a try/catch block. In the block create a LocationProvider object by getting an instance of the Criteria object. Create another try/catch block to create a Location object to request the current location of the BlackBerry device and specify the timeout period in seconds. When the getLocation() method returns, request the latitude and longitude coordinates.

   try
   {
       LocationProvider myLocationProvider =
           LocationProvider.getInstance(myCriteria);
   
       try
       {
           Location myLocation = myLocationProvider.getLocation(300);
           latitude  = myLocation.getQualifiedCoordinates().getLatitude();
           longitude = myLocation.getQualifiedCoordinates().getLongitude();
       }
       catch ( InterruptedException iex )
       {
           return;
       }
       catch ( LocationException lex )
       {
           return;
       }
   }
   catch ( LocationException lex )
   {
       return;
   }
   return;

1. Import the required classes and interface.

   import javax.microedition.location.*;

2. Create a class and a constructor.

   public class handleGPS
   {
       public handleGPS()
       {
       }
   }

3. In the constructor, create an instance of the Criteria class. Create a try/catch block. In this block, create an instance of the LocationProvider class by invoking getInstance() and using the Criteria object. Invoke setLocationListener() to specify the location of the GPS event listener.

   Criteria myCriteria = new Criteria();
   
   try
   {
       LocationProvider provider = LocationProvider.getInstance(myCriteria);
       provider.setLocationListener(new handleGPSListener(), 10, -1, -1);
   }
   catch ( LocationException lex )
   {
       return;
   }

4. In the class, implement the LocationListener interface. You must add functionality as required to this implementation.

   public static class handleGPSListener implements LocationListener
   {
      public void locationUpdated(LocationProvider provider, Location location)
      {
         if (location.isValid())
         {
             // do something
         }
         else
         {
             // invalid locatuon
         }
      }
   
      public void providerStateChanged(LocationProvider provider, int newState)
      {
         if (newState == LocationProvider.OUT_OF_SERVICE)
         {}
         else if (newState == Location.TEMPORARILY_UNAVAILABLE )
         {}
      }
   }

You can request a GPS fix and then retrieve the latitude, longitude, velocity, course heading, time stamp, and the number of satellites that the BlackBerry device is tracking.

1. Import the required classes.

   import javax.microedition.location.*;

2. Create a class and a constructor.

   public class handleGPS
   {
       public handleGPS()
       {
       }
   }

3. In the class, declare static fields for a thread and for each item of location information that you retrieve.

   static GPSThread gpsThread;
   static double latitude;
   static double longitude;
   static float  heading;
   static float  velocity;
   static long   timeStamp;
   static String nmeaString;

4. In the constructor, create and start a thread.

   gpsThread = new GPSThread();
   gpsThread.start();

5. In the class, create a private static class that extends Thread, and create a run() method.

   private static class GPSThread extends Thread
   {
      public void run()
      {
      }
   }

6. In run(), create an instance of the Criteria class. Invoke setCostAllowed(false) to specify the autonomous mode.

   Criteria myCriteria = new Criteria();
   myCriteria.setCostAllowed(false);

7. In run(), create a try/catch block. In this block create an instance of the LocationProvider class by getting an instance of the Criteria object. Create a try/catch block within this block, and create an instance of the Location class to retrieve the current GPS fix including a 300 second timeout expiry. Populate the fields, and specify the number of satellites by invoking getExtraInfo("application/X-jsr179-location-nmea").

   try
   {
      LocationProvider myLocationProvider =
         LocationProvider.getInstance(myCriteria);
   
      try
      {
         Location myLocation = myLocationProvider.getLocation(300);
   
         latitude   = myLocation.getQualifiedCoordinates().getLatitude();
         longitude  = myLocation.getQualifiedCoordinates().getLongitude();
         velocity   = myLocation.getSpeed();
         heading    = myLocation.getCourse();
         timeStamp  = myLocation.getTimestamp();
         nmeaString = myLocation.getExtraInfo
            ("application/X-jsr179-location-nmea");
      }
      catch ( InterruptedException iex )
      {}
      catch ( LocationException lex )
      {}
   }
   catch ( LocationException lex )
   {}
   
   return;

You can request a GPS fix and then retrieve the current number of satellites in view, tracked satellites, average satellite signal quality, GPS data source (internal or external GPS), and the GPS mode.

1. Import the required classes.

   import java.util.*;
   import java.lang.*;
   import net.rim.device.api.gps.*;

2. Create a class and a constructor.

   public class handleGPS
   {
      public handleGPS()
      {
      }
   }

3. In the class, declare static fields for a thread and for each item of location information that you retrieve.

   static GPSThread gpsThread;
   static int satCount;
   static int signalQuality;
   static int dataSource;
   static int gpsMode;

4. In the constructor, create and start a thread.

   gpsThread = new GPSThread();
   gpsThread.start();

5. In the class, create a private static class that extends Thread and a run() method.

   private static class GPSThread extends Thread
   {
       public void run()
       {
       }
   }

6. In run(), create a try/catch block. In this block, create an instance of the BlackBerryCriteria class that specifies the GPS mode. Create a second try/catch block. In this block create an instance of the BlackBerryLocationProvider class by getting an instance of the BlackBerryCriteria object.

   try
   {
       BlackBerryCriteria myCriteria = new BlackBerryCriteria(GPSInfo.GPS_MODE_AUTONOMOUS);
   
       try
       {
           BlackBerryLocationProvider myProvider =
               (BlackBerryLocationProvider)LocationProvider.getInstance(myCriteria);
   

7. Create a third try/catch block that is in the first try/catch block. Create a BlackBerryLocation object to retrieve the GPS fix including a 300 second timeout expiry. Populate the fields and extract the satellite information into a StringBuffer object.

   try
   {
       BlackBerryLocation myLocation =
           (BlackBerryLocation)myProvider.getLocation(300);
                       
       satCount= myLocation.getSatelliteCount();
       signalQuality = myLocation.getAverageSatelliteSignalQuality();
       dataSource = myLocation.getDataSource();
       gpsMode = myLocation.getGPSMode();
   
       SatelliteInfo si;
       StringBuffer sb = new StringBuffer("[Id:SQ:E:A]\n");
       String separator = ":";
   
       for (Enumeration e = myLocation.getSatelliteInfo();
           e!=null && e.hasMoreElements(); )
       {
           si = (SatelliteInfo)e.nextElement();
           sb.append(si.getId() + separator);
           sb.append(si.getSignalQuality() + separator);
           sb.append(si.getElevation() + separator);
           sb.append(si.getAzimuth());
           sb.append('\n');
       }
   }
   catch ( InterruptedException iex )
   {}
   catch ( LocationException lex )
   {}

You can use an instance of the LocationProvider class to automatically change the criteria that is used to track the location of a BlackBerry device.

1. Import the required classes and interface.

   import net.rim.device.api.gps.GPSInfo;
   import javax.microedition.location.*;

2. Create a class and constructor.

   public class handleGPS
   {
      public handleGPS(int gpsMode)
      {
      }
   }

3. In the class, define static fields for the location provider, latitude, longitude, altitude, speed and course.

   static LocationProvider locationProvider;
   static double lat, lon;
   static float  alt, spd, crs;

4. In the constructor, add a code block to set up a LocationProvider instance to switch to a different method of location tracking. Invoke reset() on the LocationProvider object, and then set the location listener to null to disable the listener.

   if (locationProvider != null)
   {
       locationProvider.reset();
       locationProvider.setLocationListener(null, -1, -1, -1);
   }

5. In the constructor, create and configure a Criteria object based on the GPS mode that is passed as a parameter to the constructor.

   Criteria myCriteria = new Criteria();
   myCriteria.setPreferredResponseTime(Criteria.NO_REQUIREMENT);
   myCriteria.setCostAllowed(true);
   
   if ( gpsMode == GPSInfo.GPS_MODE_AUTONOMOUS )
   {
       myCriteria.setCostAllowed(false);
   }
   else if ( gpsMode == GPSInfo.GPS_MODE_ASSIST )
   {
       myCriteria.setPreferredPowerConsumption(Criteria.POWER_USAGE_MEDIUM);
   }
   else
   {
       myCriteria.setPreferredPowerConsumption(Criteria.POWER_USAGE_LOW);
   }

6. In the constructor, create a try/catch block. In this block, create an instance of the LocationListener class by invoking getInstance() and passing the Criteria object as a parameter. Specify a location listener to handle the GPS location updates.

   try
   {
      locationProvider = LocationProvider.getInstance(myCriteria);
   
      if (locationProvider != null)
      {
         locationProvider.setLocationListener
           (new myLocationListener(), -1, -1, -1);
      }
   }
   catch (Exception err)
   {}

7. In the class, create a private static class that implements the LocationListener interface. Retrieve the current location information in the locationUpdated() method. Create a basic implementation of the providerStateChanged() method to monitor the LocationProvider state.

   private static class myLocationListener implements LocationListener
   {
      public void locationUpdated(LocationProvider provider, Location location)
      {
         lat = location.getQualifiedCoordinates().getLatitude();
         lon = location.getQualifiedCoordinates().getLongitude();
         alt = location.getQualifiedCoordinates().getAltitude();
         spd = location.getSpeed();
         crs = location.getCourse();
      }
   
      public void providerStateChanged(LocationProvider provider, int newState)
      {}
   }