参考链接：
blog.csdn.net/zhoumushui/…
package android.car.app.home.util;
import android.Manifest;
import android.car.app.home.AppManager;
import android.content.Context;
import android.content.pm.PackageManager;
import android.location.Criteria;
import android.location.GpsSatellite;
import android.location.GpsStatus;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.location.LocationProvider;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.util.Log;
import java.util.Iterator;
public class LocationHelper {
private static final String TAG = "Car_LocationHelper";
public static final int MSG_GPS_SIGNAL = 115;
public static final int MSG_GPS_SPEED = 116;
private static LocationHelper mLocationHelper;
private LocationManager mLocationManager;
private Context mContext;
private Double longitude_last_time = 0.0;
private Double latitude_last_time = 0.0;
private Double longitude_last_location = 0.0;
private Double latitude_last_location = 0.0;
private float speed_last = 0;
private int satellite_count = 0;
private int minTime = 1000;
private int minDistance = 1;
private static final double EARTH_RADIUS = 6378137.0;
private double distance;
private LocationHelper(Context context) {
this.mContext = context;
}
private final GpsStatus.Listener statusListener = new GpsStatus.Listener() {
public void onGpsStatusChanged(int event) {
if (ActivityCompat.checkSelfPermission(mContext, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
GpsStatus status = mLocationManager.getGpsStatus(null);
Log.i(TAG, "onGpsStatusChanged MaxSatellites=" + status.getMaxSatellites());
if (status != null) {
updateGpsStatus(event, status);
} else {
Log.i(TAG, "onGpsStatusChanged status=null");
}
}
};
/**
* @param event
* @param status
*/
private void updateGpsStatus(int event, GpsStatus status) {
if (status == null) {
} else if (event == GpsStatus.GPS_EVENT_SATELLITE_STATUS) {
int maxSatellites = status.getMaxSatellites();
Iterator it = status.getSatellites().iterator();
int count = 0;
while (it.hasNext() && count <= maxSatellites) {
GpsSatellite s = it.next();
if (s.getSnr() >= 35) {
count++;
Log.i(TAG, "updateGpsStatus snr=" + s.getSnr());
}
}
satellite_count = count;
Log.i(TAG, "updateGpsStatus: satellite_count=" + satellite_count);
// CarApplication.getInstance().notifyListener(MSG_GPS_SIGNAL, satellite_count);
if (satellite_count == 0) {
AppManager.getInstance().notifyListener(MSG_GPS_SPEED, 0);
}
}
}
public static LocationHelper getInstance(Context context) {
if (mLocationHelper == null) {
mLocationHelper = new LocationHelper(context);
}
return mLocationHelper;
}
public boolean requestLocationUpdate() {
Log.i(TAG, "requestLocationUpdate: ");
LocationManager locationManager = getLocationManager();
if (locationManager == null) {
return false;
}
String bestProvider = locationManager.getBestProvider(getCriteria(), true);
Log.i(TAG, "requestLocationUpdate bestProvider:" + bestProvider);
try {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, minTime, minDistance, mLocationListener);
} catch (SecurityException e) {
Log.e(TAG, "requestLocationUpdate: error=" + e.toString());
e.printStackTrace();
}
if (!locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
Log.e(TAG, "requestLocationUpdate: gps disable");
return false;
}
return true;
}
private Criteria getCriteria() {
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setCostAllowed(false);
criteria.setSpeedRequired(true);
criteria.setBearingRequired(false);
criteria.setAltitudeRequired(true);
criteria.setPowerRequirement(Criteria.POWER_HIGH);
return criteria;
}
public Location getLocation() {
LocationManager locationManager = getLocationManager();
if (locationManager == null) {
return null;
}
String bestProvider = locationManager.getBestProvider(getCriteria(), true);
Location loc = null;
try {
loc = locationManager.getLastKnownLocation(bestProvider);
} catch (SecurityException e) {
e.printStackTrace();
}
return loc;
}
private LocationManager getLocationManager() {
if (mLocationManager == null) {
mLocationManager = (LocationManager) mContext.getSystemService(Context.LOCATION_SERVICE);
if (mLocationListener == null) {
Log.e(TAG, "requestLocationUpdate: create LocationManager intance fail");
}
}
return mLocationManager;
}
public void releaseLocation() {
Log.d(TAG, "releaseLocation: ");
if (mLocationManager != null) {
try {
mLocationManager.removeUpdates(mLocationListener);
mLocationManager.removeGpsStatusListener(statusListener);
} catch (SecurityException e) {
e.printStackTrace();
}
}
mLocationManager = null;
Log.d(TAG, "releaseLocation: success");
}
public static double getDistance(double longitude1, double latitude1, double longitude2, double latitude2) {
double Lat1 = rad(latitude1);
double Lat2 = rad(latitude2);
double a = Lat1 - Lat2;
double b = rad(longitude1) - rad(longitude2);
double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2)
+ Math.cos(Lat1) * Math.cos(Lat2)
* Math.pow(Math.sin(b / 2), 2)));
s = s * EARTH_RADIUS;
s = Math.round(s * 10000) / 10000;
return s;
}
private static double rad(double d) {
return d * Math.PI / 180.0;
}
private LocationListener mLocationListener = new LocationListener() {
public void onLocationChanged(Location location) {
if (ActivityCompat.checkSelfPermission(mContext, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
mLocationManager.addGpsStatusListener(statusListener);
Log.i(TAG, "onLocationChanged: satellite_count=" + satellite_count);
Log.i(TAG, "onLocationChanged: float speed=" + location.getSpeed());
int speed = (int) (location.getSpeed() * 3.6);// m/s ---> km/h
Log.i(TAG, "onLocationChanged: speed=" + speed);
Log.i(TAG, "onLocationChanged: satellite_count=" + satellite_count);
// CarApplication.getInstance().notifyListener(MSG_GPS_SPEED, speed);
if (satellite_count >= 1) {
//当有3颗15强度的卫星时，才显示速度
AppManager.getInstance().notifyListener(MSG_GPS_SPEED, speed);
}
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
switch (status) {
case LocationProvider.AVAILABLE:
Log.d(TAG, "gps status: available");
break;
case LocationProvider.OUT_OF_SERVICE:
Log.d(TAG, "gps status: out of service");
break;
case LocationProvider.TEMPORARILY_UNAVAILABLE:
Log.d(TAG, "gps status: temporarily unavailable");
break;
default:
break;
}
}
@Override
public void onProviderEnabled(String provider) {
Log.d(TAG, "GPS onProviderEnabled");
}
@Override
public void onProviderDisabled(String provider) {
Log.d(TAG, "GPS onProviderDisabled");
}
};
}
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