Cách lấy vị trí thiết bị (Cell Location) trên Android

Lấy Cell Location (Vị trí trạm phát) trong Android

Hướng dẫn sử dụng TelephonyManager.getCellLocation() để lấy vị trí đại lược dựa trên trạm phát (cell tower). Lưu ý: Phương thức này deprecated từ API 29 (Android 10), thay thế bằng getAllCellInfo().

Bước 1: Tạo dự án mới

Android Studio → File → New Project.

Bước 2: Giao diện (res/layout/activity_main.xml)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="https://schemas.android.com/apk/res/android"
    xmlns:app="https://schemas.android.com/apk/res-auto"
    xmlns:tools="https://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/text"
        android:textSize="18sp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

Bước 3: Code logic (java/MainActivity.java)

package com.example.myapplication;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.RequiresApi;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.telephony.CellLocation;
import android.telephony.TelephonyManager;
import android.telephony.gsm.GsmCellLocation;
import android.telephony.cdma.CdmaCellLocation;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    private static final int PERMISSION_REQUEST_CODE = 100;
    TextView textView;
    TelephonyManager telephonyManager;

    @RequiresApi(api = Build.VERSION_CODES.P)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        textView = findViewById(R.id.text);
        telephonyManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);

        if (!hasPermissions()) {
            requestPermissions();
        } else {
            showCellLocation();
        }
    }

    private boolean hasPermissions() {
        return ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE) == PackageManager.PERMISSION_GRANTED
                && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED;
    }

    private void requestPermissions() {
        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.READ_PHONE_STATE, Manifest.permission.ACCESS_COARSE_LOCATION},
                PERMISSION_REQUEST_CODE);
    }

    @RequiresApi(api = Build.VERSION_CODES.P)
    private void showCellLocation() {
        // DEPRECATED API 29+
        CellLocation location = telephonyManager.getCellLocation();
        StringBuilder sb = new StringBuilder();

        if (location != null) {
            sb.append("CellLocation class: ").append(location.getClass().getSimpleName()).append("\n\n");

            if (location instanceof GsmCellLocation) {
                GsmCellLocation gsm = (GsmCellLocation) location;
                sb.append("GSM Cell Info:\n");
                sb.append("  CID (Cell ID): ").append(gsm.getCid()).append("\n");
                sb.append("  LAC (Location Area Code): ").append(gsm.getLac()).append("\n");
                sb.append("  PSC (Primary Scrambling Code): ").append(gsm.getPsc()).append("\n");
            } else if (location instanceof CdmaCellLocation) {
                CdmaCellLocation cdma = (CdmaCellLocation) location;
                sb.append("CDMA Cell Info:\n");
                sb.append("  Base Station ID: ").append(cdma.getBaseStationId()).append("\n");
                sb.append("  Network ID: ").append(cdma.getNetworkId()).append("\n");
                sb.append("  System ID: ").append(cdma.getSystemId()).append("\n");
                sb.append("  Longitude: ").append(cdma.getBaseStationLongitude()).append("\n");
                sb.append("  Latitude: ").append(cdma.getBaseStationLatitude()).append("\n");
            }
        } else {
            sb.append("CellLocation is null (cần quyền hoặc không có dịch vụ)");
        }

        sb.append("\n\n⚠️ DEPRECATED từ Android 10 (API 29).");
        sb.append("\nDùng TelephonyManager.getAllCellInfo() hoặc CellInfo API thay thế.");

        textView.setText(sb.toString());
    }

    @RequiresApi(api = Build.VERSION_CODES.P)
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == PERMISSION_REQUEST_CODE && hasPermissions()) {
            showCellLocation();
        }
    }
}

Bước 4: AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="https://schemas.android.com/apk/res/android"
    package="com.example.myapplication">

    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

    <application ...>
        <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>

⚠️ Quan trọng: Thay thế bằng CellInfo API (API 17+)

// Cách hiện đại (API 17+)
List<CellInfo> cellInfos = telephonyManager.getAllCellInfo();
if (cellInfos != null) {
    for (CellInfo info : cellInfos) {
        if (info instanceof CellInfoGsm) {
            CellIdentityGsm id = ((CellInfoGsm) info).getCellIdentity();
            // id.getCid(), id.getLac(), id.getMcc(), id.getMnc()...
        } else if (info instanceof CellInfoLte) {
            CellIdentityLte id = ((CellInfoLte) info).getCellIdentity();
            // id.getCi(), id.getTac(), id.getPci()...
        }
        // Signal strength: info.getCellSignalStrength().getDbm()
    }
}

Chạy ứng dụng

Cấp quyền → TextView hiển thị Cell ID, LAC (GSM) hoặc Base Station ID (CDMA). Trên Android 10+ thường trả về null.