Question

我已经实现了Haversine公式来计算当前用户位置与地点之间的距离，但是当我插入代码"http://maps.google.com/maps?saddr=" + gpsHandler.getLatitude() + "," + gpsHandler.getLongitude() + "&daddr=" + endlat + "," + endLng + "&mode=driving"以用于Google Map Application时，结果还有2至3公里的差距。

第一张图片：Haversine公式结果

第二张图片：Google搜索结果

要获取当前的位置坐标，我分别创建了自己的类处理程序，以便仅在实现hasrsine公式methode的另一个类中调用它。我将给出更清晰的代码。

此GPSHandler.java类可调用当前位置的用户位置

GPSHandler.java

/*
 * Copyright 2019 RONINGRUM. All rights reserved.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package co.id.roningrum.dolanapptugasakhir.handler;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.util.Log;

/**
 * Created by roningrum on 24/06/2019 2019.
 */
public class GPSHandler extends Service implements LocationListener {

    private Context context;
    private boolean isGPSEnabled = false;

    private boolean isNetworkEnabled = false;
    private boolean canGetLocation = false;

    private Location location;
    private double latitude;
    private double longitude;

    private LocationManager locationManager;
    private static final int PERMISSIONS_REQUEST_LOCATION = 99;
    private static final long MIN_DISTANCE_CHANGE_UPDATES = 10;
    private static final long MIN_TIME_BW_UPDATES = 1000 * 60;

    public GPSHandler() {
        getLocation();
    }

    public GPSHandler(Context context) {
        this.context = context;
        getLocation();
    }

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

    private Location getLocation() {
        try {
            locationManager = (LocationManager) context
                    .getSystemService(LOCATION_SERVICE);
            isGPSEnabled = locationManager
                    .isProviderEnabled(LocationManager.GPS_PROVIDER);
            isNetworkEnabled = locationManager
                    .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

            if (!isGPSEnabled && !isNetworkEnabled) {
                Log.d("Jaringan", "Tidak ada koneksi");
                return null;
            } else {
                checkLocationPermission();
                this.canGetLocation = true;
                if (isNetworkEnabled) {
                    locationManager
                            .requestLocationUpdates(
                                    LocationManager.NETWORK_PROVIDER,
                                    MIN_TIME_BW_UPDATES,
                                    MIN_DISTANCE_CHANGE_UPDATES, this);
                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(
                                        LocationManager.NETWORK_PROVIDER);
                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }
                if (isGPSEnabled) {
                    locationManager
                            .requestLocationUpdates(
                                    LocationManager.NETWORK_PROVIDER,
                                    MIN_TIME_BW_UPDATES,
                                    MIN_DISTANCE_CHANGE_UPDATES, this);
                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(
                                        LocationManager.GPS_PROVIDER);
                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();

        }
        return location;
    }

    private boolean checkLocationPermission() {

        if (ContextCompat.checkSelfPermission(context,
                android.Manifest.permission.ACCESS_FINE_LOCATION)
                != PackageManager.PERMISSION_GRANTED) {

            // No explanation needed, we can request the permission.
            ActivityCompat.requestPermissions((Activity) context,
                    new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION},
                    PERMISSIONS_REQUEST_LOCATION);
        }
        return true;
    }

    public void stopUsingGPS() {
        if (locationManager != null) {
            locationManager.removeUpdates(GPSHandler.this);
        }
    }

    public double getLatitude() {
        if (location != null) {
            latitude = location.getLatitude();
        }
        return latitude;
    }

    public double getLongitude() {
        if (location != null) {
            longitude = location.getLongitude();
        }
        return longitude;
    }

    public boolean isCanGetLocation() {
        return this.canGetLocation;
    }


    public void showSettingsAlert() {
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(context);

        // Setting Dialog Title
        alertDialog.setTitle("GPS is settings");

        // Setting Dialog Message
        alertDialog
                .setMessage("GPS is not enabled. Do you want to go to settings menu?");

        // On pressing Settings button
        alertDialog.setPositiveButton("Settings",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        Intent intent = new Intent(
                                Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                        context.startActivity(intent);
                    }
                });
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d("Working", "Service started");
        getLocation();
        return super.onStartCommand(intent, flags, startId);

    }

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

    @Override
    public void onLocationChanged(Location location) {

    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {

    }

    @Override
    public void onProviderEnabled(String provider) {

    }

    @Override
    public void onProviderDisabled(String provider) {

    }
}

对于使用Haversine公式的计算距离，我在类详细信息活动中插入了显示距离的代码。

BusDetailActivity.java

/*
 * Copyright 2019 RONINGRUM. All rights reserved.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package co.id.roningrum.dolanapptugasakhir.transportation.bus;

import android.annotation.SuppressLint;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.AppBarLayout;
import android.support.design.widget.CollapsingToolbarLayout;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.MenuItem;
import android.widget.ImageView;
import android.widget.TextView;

import com.bumptech.glide.Glide;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapView;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

import java.util.Objects;

import co.id.roningrum.dolanapptugasakhir.R;
import co.id.roningrum.dolanapptugasakhir.handler.GPSHandler;
import co.id.roningrum.dolanapptugasakhir.item.TransportationItem;

public class BusDetailActivity extends AppCompatActivity implements OnMapReadyCallback {
    public static final String EXTRA_BUS_KEY = "busKey";

    public static final String MAP_VIEW_KEY = "mapViewBundle";

    private final static String TAG = "Pesan";

    private GoogleMap busGoogleMap;
    private MapView busMapView;

    private DatabaseReference busDetailRef;

    private GPSHandler gpsHandler;
    private ValueEventListener valueEventListener;

    private TextView tvNameBusDetail, tvAddressBusDetail, tvDistanceAirport;

    private ImageView imgBusDetail;
    private CollapsingToolbarLayout collapsingToolbarBus;

    private double startLat;
    private double startlng;
    private double endlat;
    private double endLng;
    private double distance;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_bus_detail);
        tvNameBusDetail = findViewById(R.id.name_place_bus_detail);
        tvAddressBusDetail = findViewById(R.id.address_place_bus_detail);
        tvDistanceAirport = findViewById(R.id.distance_place_bus_detail);
        collapsingToolbarBus = findViewById(R.id.collapseToolbar_bus);
        busMapView = findViewById(R.id.location_bus_map_detail);
        imgBusDetail = findViewById(R.id.img_bus_detail);

        Toolbar toolbarBus = findViewById(R.id.toolbar_bus_detail);
        setSupportActionBar(toolbarBus);
        Objects.requireNonNull(getSupportActionBar()).setDisplayShowHomeEnabled(true);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);


        Bundle mapViewBundle = null;
        if (savedInstanceState != null) {
            mapViewBundle = savedInstanceState.getBundle(MAP_VIEW_KEY);
        }
        busMapView.onCreate(mapViewBundle);
        busMapView.getMapAsync(this);

        String busKey = getIntent().getStringExtra(EXTRA_BUS_KEY);
        if (busKey == null) {
            throw new IllegalArgumentException("Must pass Extra");
        }
        busDetailRef = FirebaseDatabase.getInstance().getReference().child("Transportation").child(busKey);
        gpsHandler = new GPSHandler(this);

        LoadBusDetail();


    }

    private void LoadBusDetail() {
        if (gpsHandler.isCanGetLocation()) {
            ValueEventListener eventListener = new ValueEventListener() {
                @SuppressLint("SetTextI18n")
                @Override
                public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                    final TransportationItem transportationItem = dataSnapshot.getValue(TransportationItem.class);
                    startLat = gpsHandler.getLatitude();
                    startlng = gpsHandler.getLongitude();
                    assert transportationItem != null;
                    endlat = transportationItem.getLat_transportation();
                    endLng = transportationItem.getLng_transportation();
                    distance = calculateDistance(startLat, startlng, endlat, endLng);

                    @SuppressLint("DefaultLocale") String distanceFormat = String.format("%.2f", distance);
                    tvDistanceAirport.setText("" + distanceFormat + " km");
                    tvNameBusDetail.setText(transportationItem.getName_transportation());
                    tvAddressBusDetail.setText(transportationItem.getLocation_transportation());
                    Glide.with(getApplicationContext()).load(transportationItem.getUrl_photo_transport()).into(imgBusDetail);
                    AppBarLayout appBarLayout = findViewById(R.id.app_bar_bus);
                    appBarLayout.addOnOffsetChangedListener(new AppBarLayout.BaseOnOffsetChangedListener() {
                        boolean isShow = true;
                        int scrollRange = -1;

                        @Override
                        public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
                            if (scrollRange == -1) {
                                scrollRange = appBarLayout.getTotalScrollRange();
                            }
                            if (scrollRange + verticalOffset == 0) {
                                collapsingToolbarBus.setTitle(transportationItem.getName_transportation());
                                isShow = true;
                            } else {
                                collapsingToolbarBus.setTitle(" ");
                                isShow = false;
                            }

                        }
                    });

                }

                @Override
                public void onCancelled(@NonNull DatabaseError databaseError) {
                    Log.e(TAG, "Firebase Database Error" + databaseError.getMessage());
                }
            };
            busDetailRef.addValueEventListener(eventListener);
            valueEventListener = eventListener;
        }
    }

    private double calculateDistance(double startLat, double startlng, double endlat, double endLng) {

        double earthRadius = 6371;
        double latDiff = Math.toRadians(startLat - endlat);
        double lngDiff = Math.toRadians(startlng - endLng);
        double a = Math.sin(latDiff / 2) * Math.sin(latDiff / 2) +
                Math.cos(Math.toRadians(startLat)) * Math.cos(Math.toRadians(endlat)) *
                        Math.sin(lngDiff / 2) * Math.sin(lngDiff / 2);
        double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
        double distance = earthRadius * c;

        int meterConversion = 1609;

        return (distance * meterConversion / 1000);
    }


    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        Bundle mapViewBundle = outState.getBundle(MAP_VIEW_KEY);
        if (mapViewBundle == null) {
            mapViewBundle = new Bundle();
            outState.putBundle(MAP_VIEW_KEY, mapViewBundle);
            busMapView.onSaveInstanceState(mapViewBundle);
        }

    }

    @Override
    public void onMapReady(GoogleMap googleMap) {

        busGoogleMap = googleMap;
        if (gpsHandler.isCanGetLocation()) {
            ValueEventListener eventListener = new ValueEventListener() {
                @Override
                public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                    TransportationItem transportationItem = dataSnapshot.getValue(TransportationItem.class);
                    assert transportationItem != null;
                    endlat = transportationItem.getLat_transportation();
                    endLng = transportationItem.getLng_transportation();

                    LatLng location = new LatLng(endlat, endLng);
                    busGoogleMap.addMarker(new MarkerOptions().position(location));
                    busGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(location, 16.0f));
                    busGoogleMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
                        @Override
                        public void onMapClick(LatLng latLng) {
                            String uri = "http://maps.google.com/maps?saddr=" + gpsHandler.getLatitude() + "," + gpsHandler.getLongitude() + "&daddr=" + endlat + "," + endLng + "&mode=driving";
                            Intent intent = new Intent(android.content.Intent.ACTION_VIEW, Uri.parse(uri));
                            startActivity(Intent.createChooser(intent, "Select an application"));
                        }
                    });
                }

                @Override
                public void onCancelled(@NonNull DatabaseError databaseError) {
                    Log.e(TAG, "Firebase Database Error" + databaseError.getMessage());
                }
            };
            busDetailRef.addValueEventListener(eventListener);
            valueEventListener = eventListener;

        }


    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Respond to the action bar's Up/Home button
        if (item.getItemId() == android.R.id.home) {
            finish();
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onResume() {
        super.onResume();
        busMapView.onResume();
    }

    @Override
    protected void onStart() {
        super.onStart();
        LoadBusDetail();
        busMapView.onStart();
    }

    @Override
    protected void onStop() {
        super.onStop();
        busMapView.onStop();
        busDetailRef.removeEventListener(valueEventListener);

    }

    @Override
    protected void onPause() {
        super.onPause();
        busMapView.onPause();
    }
}

对于数据endLat和endLng，我从Firebase中的数据库中获取了数据

我想显示与Google结果相距0.1 km的准确结果距离。如果您能更好地解决我的问题，我将不胜感激

为什么hasversine计算的结果与Google Driving Mode的距离不同？

0 个答案: