Categories: Java ME | Location Based Services | Location API (JSR-179) | Code Examples

This page was last modified 12:24, 19 June 2008.

From Forum Nokia Wiki

Location API is a JSR 179 which is used to find location information like latitude and longitude.

Here is a code example:

import javax.microedition.midlet.*;
   
      import javax.microedition.lcdui.*;
   
      import javax.microedition.location.*;
          
   
      public class loctest extends MIDlet implements CommandListener
   
      {
   
          private Display display;
   
          private Form form;
   
          private Command cmdExit,cmdOK;
  
          private StringItem si;
  
       
  
          public loctest()
  
          {
  
      
  
              display =Display.getDisplay(this);
  
              form = new Form("Location Api test");
                cmdExit = new Command("Exit",Command.EXIT,5);
  
             cmdOK = new Command("OK",Command.OK,1);
  
              si = new StringItem("Geo Location", "Click OK");
  
              form.append(si);
  
              form.addCommand(cmdOK);
                form.addCommand(cmdExit);
  
              form.setCommandListener(this);
  
       
            }
  
       
  
          public void startApp()
  
          {
  
              display.setCurrent(form);
  
          }
  
       
  
       
  
          public void pauseApp()
  
          {
  
       
  
          }
  
       
  
          public void destroyApp(boolean flag) {
  
              notifyDestroyed();
  
          }
  
       
  
          public void commandAction(Command c, Displayable d)
  
          {
  
              if (c == cmdOK){
  
                  Retriever ret = new Retriever(this);
  
                  ret.start();
  
       
  
              } else if (c == cmdExit) {
  
                  destroyApp(false);
  
              }
  
          }
  
       
  
          public void displayString(String string)
  
          {
  
              si.setText(string);
  
          }
  
      }
  
       
  
      class Retriever extends Thread {
  
       
  
          private loctest midlet;
  
       
  
              public Retriever(loctest midlet)
  
              {
 
  
 
                    this.midlet = midlet;
  
       
            }
  
       
  
          public void run()
  
              {
  
 
  
                  try {
  
                                  checkLocation();
  
                              } catch (Exception ex)
  
                              {
  
                                  ex.printStackTrace();
  
                                  midlet.displayString(ex.toString());
  
                  }
  
              }
  
       
  
          public void checkLocation() throws Exception
  
          {
  
              String string;
  
              Location l;
  
              LocationProvider lp;
  
              Coordinates c;
 
 
              Criteria cr= new Criteria();
 
              cr.setHorizontalAccuracy(500);
 
       
 
 
              lp= LocationProvider.getInstance(cr);
 
       
 
 
 
              l = lp.getLocation(60);
 
              c = l.getQualifiedCoordinates();
           if(c != null ) {
 
                // Use coordinate information
 
                double lat = c.getLatitude();
 
                double lon = c.getLongitude();
 
                string = "\nLatitude : " + lat + "\nLongitude : " + lon;
 
       
 
              } else {
 
                  string ="Location API failed";
 
              }
 
              midlet.displayString(string);
 
          }
 
      }