如何计算从Curent机车到其他位置Location Listener的总里程旅行？

Criteria c=new Criteria()
c.setAccuracy(Criteria.ACCURACY_FINE);                                      
String providerName=locMgr.getBestProvider(c,true);

                         Location startLocation = new Location(providerName);
                         startLocation.setLatitude(PrevLatitude);
                         startLocation.setLongitude(PrevLongitude);
                         startLocation.set(startLocation);


                         Location _myLoc = new Location(providerName);
                         _myLoc.setLatitude(Double.valueOf(nf.format(location.getLatitude())));
                         _myLoc.setLongitude(Double.valueOf(nf.format(location.getLongitude())));
                         _myLoc.set(_myLoc);


                         double meters = _myLoc.distanceTo(startLocation);
                         double miles = (meters*0.000621371192237334);

start_location

finish_location

start_location.distanceTo(finish_location)

package com.websmithing.gpstracker;

import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.location.Location;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesClient;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.location.LocationClient;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.loopj.android.http.AsyncHttpResponseHandler;
import com.loopj.android.http.RequestParams;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

public class LocationService extends Service implements
        GooglePlayServicesClient.ConnectionCallbacks,
        GooglePlayServicesClient.OnConnectionFailedListener,
        LocationListener {

    private static final String TAG = \"LocationService\";

    // use the websmithing defaultUploadWebsite for testing and then check your
    // location with your browser here: https://www.websmithing.com/gpstracker/displaymap.php
    private String defaultUploadWebsite;

    private boolean currentlyProcessingLocation = false;
    private LocationRequest locationRequest;
    private LocationClient locationClient;

    @Override
    public void onCreate() {
        super.onCreate();

        defaultUploadWebsite = getString(R.string.default_upload_website);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // if we are currently trying to get a location and the alarm manager has called this again,
        // no need to start processing a new location.
        if (!currentlyProcessingLocation) {
            currentlyProcessingLocation = true;
            startTracking();
        }

        return START_NOT_STICKY;
    }

    private void startTracking() {
        Log.d(TAG, \"startTracking\");

        if (GooglePlayServicesUtil.isGooglePlayServicesAvailable(this) == ConnectionResult.SUCCESS) {
            locationClient = new LocationClient(this,this,this);

            if (!locationClient.isConnected() || !locationClient.isConnecting()) {
                locationClient.connect();
            }
        } else {
            Log.e(TAG, \"unable to connect to google play services.\");
        }
    }

    protected void sendLocationDataToWebsite(Location location) {
        // formatted for mysql datetime format
        DateFormat dateFormat = new SimpleDateFormat(\"yyyy-MM-dd HH:mm:ss\");
        dateFormat.setTimeZone(TimeZone.getDefault());
        Date date = new Date(location.getTime());

        SharedPreferences sharedPreferences = this.getSharedPreferences(\"com.websmithing.gpstracker.prefs\", Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();

        float totalDistanceInMeters = sharedPreferences.getFloat(\"totalDistanceInMeters\", 0f);

        boolean firstTimeGettingPosition = sharedPreferences.getBoolean(\"firstTimeGettingPosition\", true);

        if (firstTimeGettingPosition) {
            editor.putBoolean(\"firstTimeGettingPosition\", false);
        } else {
            Location previousLocation = new Location(\"\");
            previousLocation.setLatitude(sharedPreferences.getFloat(\"previousLatitude\", 0f));
            previousLocation.setLongitude(sharedPreferences.getFloat(\"previousLongitude\", 0f));

            float distance = location.distanceTo(previousLocation);
            totalDistanceInMeters += distance;
            editor.putFloat(\"totalDistanceInMeters\", totalDistanceInMeters);
        }

        editor.putFloat(\"previousLatitude\", (float)location.getLatitude());
        editor.putFloat(\"previousLongitude\", (float)location.getLongitude());
        editor.apply();

        final RequestParams requestParams = new RequestParams();
        requestParams.put(\"latitude\", Double.toString(location.getLatitude()));
        requestParams.put(\"longitude\", Double.toString(location.getLongitude()));

        Double speedInMilesPerHour = location.getSpeed()* 2.2369;
        requestParams.put(\"speed\",  Integer.toString(speedInMilesPerHour.intValue()));

        try {
            requestParams.put(\"date\", URLEncoder.encode(dateFormat.format(date), \"UTF-8\"));
        } catch (UnsupportedEncodingException e) {}

        requestParams.put(\"locationmethod\", location.getProvider());

        if (totalDistanceInMeters > 0) {
            requestParams.put(\"distance\", String.format(\"%.1f\", totalDistanceInMeters / 1609)); // in miles,
        } else {
            requestParams.put(\"distance\", \"0.0\"); // in miles
        }

        requestParams.put(\"username\", sharedPreferences.getString(\"userName\", \"\"));
        requestParams.put(\"phonenumber\", sharedPreferences.getString(\"appID\", \"\")); // uuid
        requestParams.put(\"sessionid\", sharedPreferences.getString(\"sessionID\", \"\")); // uuid

        Double accuracyInFeet = location.getAccuracy()* 3.28;
        requestParams.put(\"accuracy\",  Integer.toString(accuracyInFeet.intValue()));

        Double altitudeInFeet = location.getAltitude() * 3.28;
        requestParams.put(\"extrainfo\",  Integer.toString(altitudeInFeet.intValue()));

        requestParams.put(\"eventtype\", \"android\");

        Float direction = location.getBearing();
        requestParams.put(\"direction\",  Integer.toString(direction.intValue()));

        final String uploadWebsite = sharedPreferences.getString(\"defaultUploadWebsite\", defaultUploadWebsite);

        LoopjHttpClient.get(uploadWebsite, requestParams, new AsyncHttpResponseHandler() {
            @Override
            public void onSuccess(int statusCode, org.apache.http.Header[] headers, byte[] responseBody) {
                LoopjHttpClient.debugLoopJ(TAG, \"sendLocationDataToWebsite - success\", uploadWebsite, requestParams, responseBody, headers, statusCode, null);
                stopSelf();
            }
            @Override
            public void onFailure(int statusCode, org.apache.http.Header[] headers, byte[] errorResponse, Throwable e) {
                LoopjHttpClient.debugLoopJ(TAG, \"sendLocationDataToWebsite - failure\", uploadWebsite, requestParams, errorResponse, headers, statusCode, e);
                stopSelf();
            }
        });
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onLocationChanged(Location location) {
        if (location != null) {
            Log.e(TAG, \"position: \" + location.getLatitude() + \", \" + location.getLongitude() + \" accuracy: \" + location.getAccuracy());

            // we have our desired accuracy of 500 meters so lets quit this service,
            // onDestroy will be called and stop our location uodates
            if (location.getAccuracy() < 500.0f) {
                stopLocationUpdates();
                sendLocationDataToWebsite(location);
            }
        }
    }

    private void stopLocationUpdates() {
        if (locationClient != null && locationClient.isConnected()) {
            locationClient.removeLocationUpdates(this);
            locationClient.disconnect();
        }
    }

    /**
     * Called by Location Services when the request to connect the
     * client finishes successfully. At this point, you can
     * request the current location or start periodic updates
     */
    @Override
    public void onConnected(Bundle bundle) {
        Log.d(TAG, \"onConnected\");

        locationRequest = LocationRequest.create();
        locationRequest.setInterval(1000); // milliseconds
        locationRequest.setFastestInterval(1000); // the fastest rate in milliseconds at which your app can handle location updates
        locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

        locationClient.requestLocationUpdates(locationRequest, this);
    }

    /**
     * Called by Location Services if the connection to the
     * location client drops because of an error.
     */
    @Override
    public void onDisconnected() {
        Log.e(TAG, \"onDisconnected\");

        stopLocationUpdates();
        stopSelf();
    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        Log.e(TAG, \"onConnectionFailed\");

        stopLocationUpdates();
        stopSelf();
    }
}