// =======================================
// 文件: AutoUpdateManager.java + MainActivity
// （本示例將 Manager 與 Activity 合寫于一處，注釋區(qū)分）
// =======================================
 
package com.example.autoupdate;
 
import android.Manifest;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.DownloadManager;
import android.content.ActivityNotFoundException;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.content.res.Configuration;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.FileProvider;
 
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
 
// —— Play Core 庫依賴（立即更新/靈活更新）
// implementation "com.google.android.play:core:1.10.3"
import com.google.android.play.core.appupdate.AppUpdateInfo;
import com.google.android.play.core.appupdate.AppUpdateManagerFactory;
import com.google.android.play.core.install.model.AppUpdateType;
import com.google.android.play.core.install.model.UpdateAvailability;
import com.google.android.play.core.tasks.Task;
 
import org.json.JSONObject;
 
import java.io.File;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Scanner;
 
public class MainActivity extends AppCompatActivity {
 
    // ---------- 常量區(qū) ----------
    private static final int REQUEST_CODE_UPDATE = 100;               // Play 更新請求碼
    private static final int REQUEST_INSTALL_PERMISSION = 101;        // 動態(tài)安裝權限
    private static final String TAG = "AutoUpdate";
    private long downloadId;                                          // DownloadManager 返回 ID
    private DownloadManager downloadManager;
 
    // ---------- onCreate ----------
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);  // 布局見下文
 
        // 按鈕觸發(fā)兩種更新
        Button btnPlayUpdate    = findViewById(R.id.btnPlayUpdate);
        Button btnCustomUpdate  = findViewById(R.id.btnCustomUpdate);
 
        btnPlayUpdate.setOnClickListener(new View.OnClickListener() {
            @Override public void onClick(View v) {
                checkPlayUpdate();   // Play 商店內更新
            }
        });
 
        btnCustomUpdate.setOnClickListener(new View.OnClickListener() {
            @Override public void onClick(View v) {
                checkCustomUpdate(); // 自建服務器更新
            }
        });
 
        // 初始化 DownloadManager
        downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
        // 注冊下載完成廣播
        registerReceiver(onDownloadComplete, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));
    }
 
    // ---------- 1. Play In?App Updates 檢查 ----------
    private void checkPlayUpdate() {
        // 創(chuàng)建 AppUpdateManager
        com.google.android.play.core.appupdate.AppUpdateManager appUpdateManager =
                AppUpdateManagerFactory.create(this);
 
        // 異步獲取更新信息
        Task<AppUpdateInfo> appUpdateInfoTask = appUpdateManager.getAppUpdateInfo();
        appUpdateInfoTask.addOnSuccessListener(info -> {
            // 判斷是否有更新且支持立即更新
            if (info.updateAvailability() == UpdateAvailability.UPDATE_AVAILABLE
                    && info.isUpdateTypeAllowed(AppUpdateType.FLEXIBLE)) {
                try {
                    // 發(fā)起靈活更新請求
                    appUpdateManager.startUpdateFlowForResult(
                            info,
                            AppUpdateType.FLEXIBLE,
                            this,
                            REQUEST_CODE_UPDATE);
                } catch (Exception e) {
                    Log.e(TAG, "Play 更新啟動失敗", e);
                }
            } else {
                Toast.makeText(this, "無可用更新或不支持此更新類型", Toast.LENGTH_SHORT).show();
            }
        });
    }
 
    // ---------- 2. 自建服務器版本檢測 ----------
    private void checkCustomUpdate() {
        new Thread(() -> {
            try {
                // 1) 請求服務器 JSON
                URL url = new URL("https://your.server.com/latest_version.json");
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setConnectTimeout(5000);
                conn.setRequestMethod("GET");
                InputStream in = conn.getInputStream();
                Scanner sc = new Scanner(in).useDelimiter("\\A");
                String json = sc.hasNext() ? sc.next() : "";
                JSONObject obj = new JSONObject(json);
                final int serverVersionCode = obj.getInt("versionCode");
                final String apkUrl       = obj.getString("apkUrl");
                final String changeLog   = obj.getString("changeLog");
 
                // 2) 獲取本地版本號
                int localVersionCode = getPackageManager()
                        .getPackageInfo(getPackageName(), 0).versionCode;
 
                if (serverVersionCode > localVersionCode) {
                    // 有新版，回到主線程彈窗提示
                    runOnUiThread(() ->
                        showUpdateDialog(apkUrl, changeLog)
                    );
                } else {
                    runOnUiThread(() ->
                        Toast.makeText(this, "已是最新版本", Toast.LENGTH_SHORT).show()
                    );
                }
            } catch (Exception e) {
                Log.e(TAG, "檢查更新失敗", e);
            }
        }).start();
    }
 
    // ---------- 3. 彈出更新對話框 ----------
    private void showUpdateDialog(String apkUrl, String changeLog) {
        new AlertDialog.Builder(this)
            .setTitle("發(fā)現新版本")
            .setMessage(changeLog)
            .setCancelable(false)
            .setPositiveButton("立即更新", (dialog, which) -> {
                startDownload(apkUrl);
            })
            .setNegativeButton("稍后再說", null)
            .show();
    }
 
    // ---------- 4. 啟動系統(tǒng) DownloadManager 下載 APK ----------
    private void startDownload(String apkUrl) {
        DownloadManager.Request request = new DownloadManager.Request(Uri.parse(apkUrl));
        request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI
                                      | DownloadManager.Request.NETWORK_MOBILE);
        request.setTitle("正在下載更新包");
        request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, "update.apk");
        // 開始下載
        downloadId = downloadManager.enqueue(request);
    }
 
    // ---------- 5. 監(jiān)聽下載完成，觸發(fā)安裝 ----------
    private BroadcastReceiver onDownloadComplete = new BroadcastReceiver() {
        @Override public void onReceive(Context context, Intent intent) {
            long id = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1);
            if (id != downloadId) return;
 
            // 下載完成，安裝 APK
            File apkFile = new File(Environment.getExternalStoragePublicDirectory(
                            Environment.DIRECTORY_DOWNLOADS), "update.apk");
 
            // Android 8.0+ 需要請求安裝未知應用權限
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                boolean canInstall = getPackageManager().canRequestPackageInstalls();
                if (!canInstall) {
                    // 請求“安裝未知應用”權限
                    ActivityCompat.requestPermissions(MainActivity.this,
                        new String[]{Manifest.permission.REQUEST_INSTALL_PACKAGES},
                        REQUEST_INSTALL_PERMISSION);
                    return;
                }
            }
            installApk(apkFile);
        }
    };
 
    // ---------- 6. 處理未知來源權限申請結果 ----------
    @Override
    public void onRequestPermissionsResult(int requestCode,
                                           @NonNull String[] permissions,
                                           @NonNull int[] grantResults) {
        if (requestCode == REQUEST_INSTALL_PERMISSION) {
            if (grantResults.length>0 && grantResults[0]==PackageManager.PERMISSION_GRANTED) {
                // 再次觸發(fā)安裝（假設 APK 仍在下載目錄）
                File apkFile = new File(Environment.getExternalStoragePublicDirectory(
                                Environment.DIRECTORY_DOWNLOADS), "update.apk");
                installApk(apkFile);
            } else {
                Toast.makeText(this, "安裝權限被拒絕，無法自動更新", Toast.LENGTH_LONG).show();
            }
        }
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }
 
    // ---------- 7. 安裝 APK 輔助方法 ----------
    private void installApk(File apkFile) {
        Uri apkUri = FileProvider.getUriForFile(this,
                getPackageName() + ".fileprovider", apkFile);
 
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setDataAndType(apkUri, "application/vnd.android.package-archive");
        intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        try {
            startActivity(intent);
        } catch (ActivityNotFoundException e) {
            Toast.makeText(this, "無法啟動安裝程序", Toast.LENGTH_LONG).show();
        }
    }
 
    // ---------- 8. Activity 銷毀時注銷 Receiver ----------
    @Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver(onDownloadComplete);
    }
}

<!-- ======================================
文件: AndroidManifest.xml
注意：需要配置 FileProvider 與權限
====================================== -->
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.autoupdate">
 
    <!-- 安裝未知來源權限（Android 8.0+ 需動態(tài)申請） -->
    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES"/>
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
 
    <application
        android:allowBackup="true"
        android:label="@string/app_name"
        android:theme="@style/Theme.AppCompat.Light.NoActionBar">
 
        <!-- FileProvider 聲明 -->
        <provider
            android:name="androidx.core.content.FileProvider"
            android:authorities="${applicationId}.fileprovider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/file_paths" />
        </provider>
 
        <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>

<!-- ======================================
文件: res/xml/file_paths.xml
FileProvider 路徑配置
====================================== -->
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="download" path="Download/"/>
</paths>

<!-- ======================================
文件: res/layout/activity_main.xml
簡單示例界面
====================================== -->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:gravity="center"
    android:layout_width="match_parent" android:layout_height="match_parent"
    android:padding="24dp">
 
    <Button
        android:id="@+id/btnPlayUpdate"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Play In?App 更新"/>
 
    <View android:layout_height="16dp" android:layout_width="match_parent"/>
 
    <Button
        android:id="@+id/btnCustomUpdate"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="自建服務更新"/>
</LinearLayout>