java - 几个小时后前台服务停止

Question

我有一个应用程序，它使用 3 个前台服务来使用 BluetoothLeScanner 扫描和处理信标。其中只有一个具有扫描代码，另外两个服务处理扫描的信标并进行一些 api 调用。 几个小时后，前台服务停止工作并且通知消失。

扫描是通过ScanCallback onScanResult进行的。每 5 分钟重新启动一次扫描，以避免 Android 停止扫描。

我使用 START_STICKY 运行前台服务。我制作了一个广播接收器，当调用 onDestroy() 方法时，它会重新启动服务。

 @Override
    public void onCreate() {
        Log.i("EntryDetectionService", "Starting Service");
        super.onCreate();
        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            String CHANNEL_ID = "Beacon Reader";
            String CHANNEL_NAME = "Scanning Beacons";

            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, CHANNEL_NAME, NotificationManager.IMPORTANCE_HIGH);
            ((NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE)).createNotificationChannel(channel);

            Notification notification = new NotificationCompat.Builder(this, CHANNEL_ID)
                    .setCategory(Notification.CATEGORY_SERVICE).setPriority(PRIORITY_HIGH)
                    .setSmallIcon(R.drawable.ic_launcher)
                    .build();

            startForeground(101, notification);
        }
    }

  @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        this.getBluetoothScanner();
        mainLoopHandler.post(scan);

        return START_STICKY;
    }

    ScanSettings settings = new ScanSettings.Builder()
                .setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
                .build();

    List<ScanFilter> filters = new ArrayList<>();
    ScanFilter filter = new ScanFilter.Builder()
             .setManufacturerData(76, new byte[] {})
             .build();
     filters.add(filter);

     if (bluetoothAdapter.isEnabled())
         bleScanner.startScan(filters, settings, scanCallback);

谢谢!!

Answer 1

保持APP存活 当 api>21 时，可以使用 JobScheduler

某些设备可能会使应用程序保持 Activity 状态。

jobScheduler android example code

当onStartJob时检查服务是否存活

public boolean isServiceRunning(Context context, String serviceName) {
        boolean isRunning = false;
        ActivityManager am = (ActivityManager) this
            .getSystemService(Context.ACTIVITY_SERVICE);
        List<ActivityManager.RunningAppProcessInfo> lists = am.getRunningAppProcesses();

        for (ActivityManager.RunningAppProcessInfo info : lists) {
            System.out.println(info.processName);
            if (info.processName.equals(serviceName)) {
                isRunning = true;
            }
        }
        return isRunning;

    }