我有一个监听电源连接事件的广播接收器。每当设备连接到电源时，我都会尝试将文件从 APP 传输到运行 Ubuntu 的机器上的服务器。文件通过蓝牙传输。由于文件传输很重要，如果由于任何原因传输出错，或者第一次尝试连接不成功，我最多重试 6 次，每次尝试之间留出 3 分钟。
一开始，我使用的是一个异步任务，只要我们仍然可以重试并且文件传输没有成功完成，它就会保持活动状态。我读到，在广播接收器中有一个 asynctask 并不是一个完全有意义的好习惯，特别是因为我强迫任务运行很长时间。因此，我决定更改为 JobIntentService，这样每次接收器捕获到电源连接事件时，我都会发出将文件传输到我的计算机的作业。在作业中，在文件传输完成或失败后，我会设置一个警报，向广播发送待处理的意图并再次调用作业。
我正在运行它，我注意到（与以前不同）在传输过程中我收到太多“对等连接重置”错误，这让我想知道作业是否在完成之前被停止或类似的东西？ . 这些错误过去在我之前的实现中不会发生。然后，我还注意到，由于某种原因，操作系统似乎再次启动了 JobIntentService（没有启动它的事件），这导致我的代码不一致并导致我丢失了一些文件（我不应该允许此作业的多个实例同时运行）
我的问题是，为什么您认为服务已重新启动？JobIntentService 是否可以在 BT 传输期间由操作系统完成并重新启动？这些文件很重，因此需要几分钟才能从应用程序传输到机器。我正在考虑尝试使用前台服务而不是 JobIntent 并通知该服务或返回我之前的实现。
有什么建议么？
这就是我所说的 Intent Job。
FileTransferJob.isJobAlreadyRunning = true;
Intent intent = new Intent(context, FileTransferJob.class);
intent.putExtra(TRANSFER_DATA_RETRIES, retries);
FileTransferJob.enqueueWork(context,intent);
这是 JobIntentService 类
public class FileTransferJob extends JobIntentService {
/**
* Unique job ID for this service.
*/
public static boolean isJobAlreadyRunning = false; //This flag will remain true as soon as this JOB is called and as long as retries are still available
public static final int JOB_ID = 1000;
public static int MAX_NUM_OF_RETRIES = 6;//How many times are we going to retry to send the data
private int MINUTES_TO_WAIT = 3; //The minutes we wait between each attempt
public String TAG = "FileTransferJob";
/**
* Convenience method for enqueuing work in to this service.
*/
public static void enqueueWork(Context context, Intent work) {
enqueueWork(context, FileTransferJob.class, JOB_ID, work);
}
@Override
protected void onHandleWork(Intent intent) {
int retriesRemaining = intent.getIntExtra(TRANSFER_DATA_RETRIES,1); //Get the number of retries we have. Default to 1 (this one)
Log.d(TAG, "onHandleWork: About to attempt transfer with remaining retries " + String.valueOf(retriesRemaining));
try {
BluetoothFileTransfer btio = new BluetoothFileTransfer();
Log.d(TAG, "onHandleWork: About to send data over Bluetooth");
btio.sendData(FileTransferJob.this.getApplicationContext());
FileTransferJob.isJobAlreadyRunning = false; //Success, then this is no longer running
Log.d(TAG, "onHandleWork: The data has been sent over Bluetooth");
}catch (Exception e){
Log.d(TAG, "onHandleWork: There was a problem with the BT transfer: " + e.getMessage());
retriesRemaining--; //We reduce the number of retries we have
//If no more retries available, simply do nothing
if (retriesRemaining > 0) {
Log.d(TAG, "onHandleWork: Setting up alarm. Retries ramaining: " + String.valueOf(retriesRemaining));
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
Intent alarmIntent = new Intent(this.getApplicationContext(), DataCollectReceiver.class);
alarmIntent.setAction(TRANSFER_DATA);
alarmIntent.putExtra(TRANSFER_DATA_RETRIES, retriesRemaining);
PendingIntent alarmPendingIntent = PendingIntent.getBroadcast( this.getApplicationContext(), PENDING_INTENT_CODE_FILE_TRANSFER_JOB, alarmIntent, PendingIntent.FLAG_UPDATE_CURRENT);
int totalTime = MINUTES_TO_WAIT*60*1000;
if(alarmManager != null){
alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP,
System.currentTimeMillis() + totalTime,
alarmPendingIntent);
Log.d(TAG, "onHandleWork: Alarm is set, waiting " + String.valueOf(totalTime) + " minutes for next attempt...");
}else{
Log.d(TAG, "onHandleWork: Alarm could not be set. Alarm manager is NULL");
}
}else{
Log.d(TAG, "onHandleWork: There are no more retries");
FileTransferJob.isJobAlreadyRunning = false;
}
}
}
@Override
public void onDestroy() {
super.onDestroy();
Log.d(TAG, "onDestroy: The file transfer JOB has finished");
}
}
日志猫。突出显示的部分显示了我认为操作系统创建 JobService 的新实例并运行它。
