Cách lấy địa chỉ đầy đủ từ vĩ độ và kinh độ trên Android

Giới thiệu

Ví dụ này minh họa cách chuyển đổi tọa độ địa lý (latitude, longitude) thành địa chỉ đầy đủ (reverse geocoding) trong ứng dụng Android. Chúng ta sẽ sử dụng Geocoder và LocationManager để thực hiện việc này.

Các bước thực hiện

Bước 1: Tạo dự án mới

Mở Android Studio, chọn File → New Project và điền đầy đủ thông tin cần thiết.

Bước 2: Thiết kế giao diện (activity_main.xml)

<RelativeLayout
    xmlns:android="https://schemas.android.com/apk/res/android"
    xmlns:tools="https://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="16sp"
    tools:context=".MainActivity">
    <TextView
        android:text=""
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/textView" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="40dp"
        android:text="Hiển thị địa chỉ"
        android:id="@+id/btnShowAddress"
        android:layout_centerHorizontal="true" />
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/tvAddress"
        android:layout_alignParentBottom="true"
        android:layout_marginBottom="134dp"
        android:layout_alignParentEnd="true" />
</RelativeLayout>

Bước 3: Code chính (MainActivity.java)

import android.support.v7.app.AppCompatActivity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.provider.Settings;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    Button btnShowAddress;
    TextView tvAddress;
    Location location;
    AppLocationService appLocationService;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        tvAddress = findViewById(R.id.tvAddress);
        appLocationService = new AppLocationService(MainActivity.this);
        btnShowAddress = findViewById(R.id.btnShowAddress);
        
        btnShowAddress.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                location = appLocationService.getLocation(LocationManager.GPS_PROVIDER);
                double latitude = 13.1000727;
                double longitude = 80.2126274;
                LocationAddress locationAddress = new LocationAddress();
                locationAddress.getAddressFromLocation(latitude, longitude, getApplicationContext(), new GeoCodeHandler());
                showSettingsAlert();
            }
            
            public void showSettingsAlert() {
                AlertDialog.Builder alertDialog = new AlertDialog.Builder(MainActivity.this);
                alertDialog.setTitle("CÀI ĐẶT");
                alertDialog.setMessage("Bật nhà cung cấp vị trí! Vào menu cài đặt?");
                alertDialog.setPositiveButton("Cài đặt", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                        MainActivity.this.startActivity(intent);
                    }
                });
                alertDialog.setNegativeButton("Hủy", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.cancel();
                    }
                });
                alertDialog.show();
            }
            
            class GeoCodeHandler extends Handler {
                @Override
                public void handleMessage(Message message) {
                    String locationAddress;
                    switch (message.what) {
                        case 1:
                            Bundle bundle = message.getData();
                            locationAddress = bundle.getString("address");
                            break;
                        default:
                            locationAddress = null;
                    }
                    tvAddress.setText(locationAddress);
                }
            }
        });
    }
}

Bước 4: Lớp dịch vụ vị trí (AppLocationService.java)

import android.annotation.SuppressLint;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;

@SuppressLint("Registered")
public class AppLocationService extends Service implements LocationListener {
    protected LocationManager locationManager;
    Location location;
    private static final long MIN_DISTANCE_FOR_UPDATE = 10;
    private static final long MIN_TIME_FOR_UPDATE = 1000 * 60 * 2;

    public AppLocationService(Context context) {
        locationManager = (LocationManager) context.getSystemService(LOCATION_SERVICE);
    }

    @SuppressLint("MissingPermission")
    public Location getLocation(String provider) {
        if (locationManager.isProviderEnabled(provider)) {
            locationManager.requestLocationUpdates(provider, MIN_TIME_FOR_UPDATE, MIN_DISTANCE_FOR_UPDATE, this);
            if (locationManager != null) {
                location = locationManager.getLastKnownLocation(provider);
                return location;
            }
        }
        return null;
    }

    @Override public void onLocationChanged(Location location) {}
    @Override public void onProviderDisabled(String provider) {}
    @Override public void onProviderEnabled(String provider) {}
    @Override public void onStatusChanged(String provider, int status, Bundle extras) {}
    @Override public IBinder onBind(Intent arg0) { return null; }
}

Bước 5: Lớp xử lý địa chỉ (LocationAddress.java)

import android.content.Context;
import android.location.Address;
import android.location.Geocoder;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import java.io.IOException;
import java.util.List;
import java.util.Locale;

class LocationAddress {
    private static final String TAG = "LocationAddress";
    
    static void getAddressFromLocation(final double latitude, final double longitude, final Context context, final Handler handler) {
        Thread thread = new Thread() {
            @Override
            public void run() {
                Geocoder geocoder = new Geocoder(context, Locale.getDefault());
                String result = null;
                try {
                    List<Address> addressList = geocoder.getFromLocation(latitude, longitude, 1);
                    if (addressList != null && addressList.size() > 0) {
                        Address address = addressList.get(0);
                        StringBuilder sb = new StringBuilder();
                        for (int i = 0; i < address.getMaxAddressLineIndex(); i++) {
                            sb.append(address.getAddressLine(i)).append("\n");
                        }
                        sb.append(address.getLocality()).append("\n");
                        sb.append(address.getPostalCode()).append("\n");
                        sb.append(address.getCountryName());
                        result = sb.toString();
                    }
                } catch (IOException e) {
                    Log.e(TAG, "Unable connect to Geocoder", e);
                } finally {
                    Message message = Message.obtain();
                    message.setTarget(handler);
                    if (result != null) {
                        message.what = 1;
                        Bundle bundle = new Bundle();
                        result = "Latitude: " + latitude + " Longitude: " + longitude + "\n\nAddress:\n" + result;
                        bundle.putString("address", result);
                        message.setData(bundle);
                    } else {
                        message.what = 1;
                        Bundle bundle = new Bundle();
                        result = "Latitude: " + latitude + " Longitude: " + longitude + "\n Unable to get address for this lat-long.";
                        bundle.putString("address", result);
                        message.setData(bundle);
                    }
                    message.sendToTarget();
                }
            }
        };
        thread.start();
    }
}

Bước 6: Cấu hình Manifest (AndroidManifest.xml)

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="https://schemas.android.com/apk/res/android" package="app.com.sample">
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

Chạy ứng dụng

Kết nối thiết bị Android, nhấn Run trong Android Studio và kiểm tra kết quả.