lbsmidlet.java

一个关于JSR179全球定位系统的应用程序例子

package com.myfistlbsapp;

import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.StringItem;
import javax.microedition.lcdui.TextField;
import javax.microedition.location.Coordinates;
import javax.microedition.location.Criteria;
import javax.microedition.location.Location;
import javax.microedition.location.LocationException;
import javax.microedition.location.LocationListener;
import javax.microedition.location.LocationProvider;
import javax.microedition.location.ProximityListener;
import javax.microedition.location.QualifiedCoordinates;
import javax.microedition.midlet.MIDlet;

public class LBSMIDlet extends MIDlet implements CommandListener, LocationListener, ProximityListener {
	
	private Command exitCommand;
    private Command startCommand;
    private Command waypointCommand, tolocationCommand,towaypointCommand;
    private Form locationForm,waypointForm,noAPIForm;
    private int lat,lon,alt,speed,course,dist,state,proximity;
    private int waylat,waylon,wayrad,wayalt;
    private double wplat,wplon,wpalt,wprad;
    private Display display;
    
//    private static PositionTestApp instance;
    
    private Coordinates oldCoordinates = null, curCoordinates = null;
    int az = 0;
    LocationProvider lp = null;
    private float distance = 0;
    
    public LBSMIDlet(){
    	
    	locationForm = new Form("Location Details");
    	waypointForm = new Form("New Waypoint");
    	noAPIForm = new Form("No Location API");
        exitCommand = new Command("Exit", Command.EXIT, 1);
        startCommand = new Command("Start", Command.OK, 1);
        waypointCommand = new Command("Create", Command.OK, 1);
        tolocationCommand = new Command("Location",Command.EXIT,1);
        towaypointCommand = new Command("New Waypoint",Command.OK,1);
        
        lat = locationForm.append(new StringItem("Latitude ", ""));
        lon = locationForm.append(new StringItem("Longitude ",""));
        alt = locationForm.append(new StringItem("Altitude ",""));
        speed = locationForm.append(new StringItem("Speed ",""));
        course = locationForm.append(new StringItem("Course ",""));
        dist = locationForm.append(new StringItem("Distance ",""));
        state = locationForm.append(new StringItem("",""));
        proximity = locationForm.append(new StringItem("",""));
        
        waylat = waypointForm.append(new TextField("Latitude     ","",9,TextField.DECIMAL));
        waylon = waypointForm.append(new TextField("Longitude    ","",9,TextField.DECIMAL));
        wayalt = waypointForm.append(new TextField("Altitude (m) ","",9,TextField.DECIMAL));
        wayrad = waypointForm.append(new TextField("Radius (m)   ","",9,TextField.DECIMAL));
        
        noAPIForm.append(new StringItem("This device does not support the JSR 179 Location API",""));
    }

	protected void startApp() {
		display = Display.getDisplay(this);
		
		waypointForm.addCommand(waypointCommand);
		waypointForm.addCommand(tolocationCommand);
		waypointForm.setCommandListener(this);
		
		locationForm.addCommand(exitCommand);
		locationForm.addCommand(startCommand);
		locationForm.addCommand(towaypointCommand);
        locationForm.setCommandListener(this);
        
        noAPIForm.addCommand(exitCommand);
        
        if (hasLocationAPI()){
        	createLocationProvider();
        	display.setCurrent(locationForm);
        } else
        	display.setCurrent(noAPIForm);
        
	}

	protected void pauseApp() {
	}

	protected void destroyApp(boolean arg0) {
	}
	
	public void commandAction(Command command, Displayable displayable) {
		
		if(command == exitCommand)
        {
            destroyApp(false);
            notifyDestroyed();
        } 
		else if(command == startCommand){
			Thread getLocationThread = new Thread() {
				public void run(){
					setListener();
					}
				};
				getLocationThread.start();
			}
		else if (command == towaypointCommand){
			display.setCurrent(waypointForm);
		}
		else if (command == waypointCommand){
			wplat = Double.valueOf(((
					TextField)waypointForm.get(waylat)).getString()).doubleValue();
			wplon = Double.valueOf(((
					TextField)waypointForm.get(waylon)).getString()).doubleValue();
			wpalt = Double.valueOf(((
					TextField)waypointForm.get(wayalt)).getString()).doubleValue();
			wprad = Double.valueOf(((
					TextField)waypointForm.get(wayrad)).getString()).doubleValue();

			final Coordinates waypoint = new Coordinates((float) wplat,(float) wplon,
					(float) wpalt);
			Thread getProximityThread = new Thread() {
				public void run(){
					setProximity(waypoint,wprad);
				}
			};
			getProximityThread.start();
		}
		else if (command == tolocationCommand){
			display.setCurrent(locationForm);
		}
	}
	
    void createLocationProvider() {
        if ( lp==null ) {
        	
            Criteria cr = new Criteria();
            
            try {
                lp = LocationProvider.getInstance(cr);
            } catch (LocationException le) {
                le.printStackTrace();
            }    
        }
    }

	public void locationUpdated(final LocationProvider locProvider, final Location loc) {
		
		Thread getLocationThread = new Thread(){
			public void run(){
				getLocation(locProvider,loc);
			}
		};
		getLocationThread.start();
	}

	public void providerStateChanged(LocationProvider locProvider, int newstate) {
		
		((StringItem)locationForm.get(state)).setLabel("Location Provider State Changed. Location Provider now ");
		if (newstate == LocationProvider.AVAILABLE)
			((StringItem)locationForm.get(state)).setText("AVAILABLE");
		else if (newstate == LocationProvider.TEMPORARILY_UNAVAILABLE)
			((StringItem)locationForm.get(state)).setText("TEMPORARILY_UNAVAILABLE");
		else if (newstate == LocationProvider.OUT_OF_SERVICE)
			((StringItem)locationForm.get(state)).setText("OUT_OF_SERVICE");	
	}
	
	public void monitoringStateChanged(boolean arg0) {
		
		((StringItem)locationForm.get(state)).setLabel("Monitoring State Changed. ");
		if (arg0 == false)
			((StringItem)locationForm.get(state)).setText("Not currently monitoring");
		else if (arg0 == true)
			((StringItem)locationForm.get(state)).setText("Currently Monitoring");
	}

	public void proximityEvent(final Coordinates coordinates, final Location loc) {
		Thread getLocationThread = new Thread(){
			public void run(){
				getLocation(coordinates,loc);
			}
		};
		getLocationThread.start();
	}
	
	public boolean hasLocationAPI(){
		
		if (System.getProperty("microedition.location.version") == null) {
			return false;
		} else {
		    return true;
		}
	}
	
	private void setListener(){
		lp.setLocationListener(this,2,-1,-1);
	}
	
	private void setProximity(Coordinates waypoint, double wprad){
		try {
			LocationProvider.addProximityListener(this,waypoint,(float) wprad);
		} catch (LocationException e) {
			e.printStackTrace();
		}
	}
	
	private void getLocation(LocationProvider locProvider, Location loc){
		getLocation(loc);
		((StringItem)locationForm.get(proximity)).setLabel("You are outside the " +
				wprad +	" meter radius of the defined zone");
	}
	
	private void getLocation(Coordinates c, Location loc){
		getLocation(loc);
		((StringItem)locationForm.get(proximity)).setLabel("You are " +
				loc.getQualifiedCoordinates().distance(c) + 
				" meters from (lat/long/alt)" +
				c.getLatitude()+"/"+c.getLongitude()+"/"+c.getAltitude());
		setProximity(c,wprad);
	}
	
	private void getLocation(Location loc){
		try {
			QualifiedCoordinates c = loc.getQualifiedCoordinates();
			if (null == oldCoordinates){
				oldCoordinates = new Coordinates(c.getLatitude(),c.getLongitude(),c.getAltitude());
			}
			else{
				distance += c.distance(oldCoordinates);
				curCoordinates = new Coordinates(c.getLatitude(),c.getLongitude(),c.getAltitude());
				az = (int)oldCoordinates.azimuthTo(curCoordinates);
				oldCoordinates.setAltitude(c.getAltitude());
				oldCoordinates.setLatitude(c.getLatitude());
				oldCoordinates.setLongitude(c.getLongitude());
			}
						
			if (c != null){
				((StringItem)locationForm.get(lat)).setText(String.valueOf(c.getLatitude()));
				((StringItem)locationForm.get(lon)).setText(String.valueOf(c.getLongitude()));
				((StringItem)locationForm.get(alt)).setText(String.valueOf(c.getAltitude())+" m");
				((StringItem)locationForm.get(speed)).setText(String.valueOf(loc.getSpeed()/1000*3600)+" km/h");
				((StringItem)locationForm.get(course)).setText(String.valueOf(az)+" "+findDirection(az));
				((StringItem)locationForm.get(dist)).setText(String.valueOf(distance/1000)+" km");
			}
			
		} catch (SecurityException se) {
			// The MIDlet is not authorized to retrieve location information
		}
	}
	
	private String findDirection(int azimuth){
		
		if ((azimuth >= 337 && azimuth <= 360) || (azimuth >= 0 && azimuth < 23))
			return "N";
		if (azimuth >= 23 && azimuth < 68)
			return "NE";
		if (azimuth >= 68 && azimuth < 113)
			return "E";
		if (azimuth >= 113 && azimuth < 158)
			return "SE";
		if (azimuth >= 158 && azimuth < 203)
			return "S";
		if (azimuth >= 203 && azimuth < 248)
			return "SW";
		if (azimuth >= 248 && azimuth < 293)
			return "W";
		if (azimuth >= 293 && azimuth < 337)
			return "NW";
		
		return null;
		
	}
}