安卓奥利奥上的前台服务被杀

Question

我正在尝试建立一个每分钟请求设备位置的服务。

即使应用程序关闭，我也需要在后台工作。到目前为止，我设法让它在具有奥利奥之前的 android 操作系统的设备上工作，但现在我正在 android Oreo 设备上测试该服务，当我关闭应用程序或将应用程序置于后台时无法正常工作。

在我的研究中，我发现对于 Oreo 设备，应该使用带有持续通知的前台服务来实现这一点，因此首先，我已经实现了如下所示的简单前台服务，它在应用程序启动时显示持续通知，并在应用程序停止时删除。

public class MyForegroundService extends Service {
private static String TAG = MyForegroundService.class.getSimpleName();
private static final String CHANNEL_ID = "channel_01";
private static final int NOTIFICATION_ID = 12345678;
private NotificationManager mNotificationManager;
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
public MyForegroundService() {
super();
}
@Override
public void onCreate() {
super.onCreate();
Log.d(TAG, "onCreate");
mNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
// Android O requires a Notification Channel.
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
CharSequence name = getString(R.string.app_name);
// Create the channel for the notification
NotificationChannel mChannel = new NotificationChannel(CHANNEL_ID, name, NotificationManager.IMPORTANCE_DEFAULT);
// Set the Notification Channel for the Notification Manager.
mNotificationManager.createNotificationChannel(mChannel);
}
startForeground(NOTIFICATION_ID, getNotification());
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.d(TAG, "onStartCommand");
return super.onStartCommand(intent, flags, startId);
}
@Override
public void onDestroy() {
super.onDestroy();
Log.d(TAG, "onDestroy");
stopForeground(true);
}
private Notification getNotification() {
// Get the application name from the Settings
String appName = PrefApp.getSettings(getApplicationContext()).getAppConfigs().getAppName();
String applicationKey = PrefApp.getSettings(getApplicationContext()).getAppConfigs().getAppKey();
NotificationCompat.Builder builder = new NotificationCompat.Builder(this)
.setContentTitle(appName)
.setContentText("Services are running")
.setOngoing(true)
.setPriority(Notification.PRIORITY_HIGH)
.setSmallIcon(R.mipmap.ic_notification)
.setWhen(System.currentTimeMillis());
// Set the Channel ID for Android O.
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
builder.setChannelId(CHANNEL_ID); // Channel ID
}
return builder.build();
}
}

我使用以下函数启动和停止上述服务。

public void startMyForegroundService() {
Log.d(TAG, "Start Foreground Service");
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
startForegroundService(new Intent(getApplicationContext(), MyForegroundService.class));
} else {
startService(new Intent(getApplicationContext(), MyForegroundService.class));
}
}
public void stopMyForegroundService() {
Log.d(TAG, "Stop Foreground Service");
stopService(new Intent(getApplicationContext(), MyForegroundService.class));
}

我正在测试上述服务，由于某种原因，该服务在我启动大约 30 分钟后被终止。谁能告诉我我是否做错了什么，或者可能指导我找到适合我的解决方案？

注意：我已经按照本教程并测试了他们的应用程序，但它仍然无法正常工作。该服务将在一段时间后被终止。

基本上，我的目标是实现一个可以在后台运行(即使应用程序关闭(的服务，并且每分钟获取一次位置更新。

Answer 1

您可以将 Firebase 作业调度程序用于后台服务。

法典： 添加此依赖项：

implementation 'com.firebase:firebase-jobdispatcher:0.8.5'
public class MyJobService extends JobService
{
private static final String TAG = MyJobService.class.getSimpleName();
@Override
public boolean onStartJob(JobParameters job)
{
Log.e(TAG, "onStartJob: my job service class is called.");
// enter the task you want to perform.
return false;
}
@Override
public boolean onStopJob(JobParameters job)
{
return false;
}
}

在活动中创建一个作业，您可以按照过去为后台服务执行的方式进行操作。

/**
* 2018 September 27 - Thursday - 06:36 PM
* create job method
*
* this method will create job
**/
private static Job createJob(FirebaseJobDispatcher dispatcher)
{
return dispatcher.newJobBuilder()
//persist the task across boots
.setLifetime(Lifetime.FOREVER)
//.setLifetime(Lifetime.UNTIL_NEXT_BOOT)
//call this service when the criteria are met.
.setService(MyJobService.class)
//unique id of the task
.setTag("TAGOFTHEJOB")
//don't overwrite an existing job with the same tag
.setReplaceCurrent(false)
// We are mentioning that the job is periodic.
.setRecurring(true)
// Run every 30 min from now. You can modify it to your use.
.setTrigger(Trigger.executionWindow(1800, 1800))
// retry with exponential backoff
.setRetryStrategy(RetryStrategy.DEFAULT_LINEAR)
//.setRetryStrategy(RetryStrategy.DEFAULT_EXPONENTIAL)
//Run this job only when the network is available.
.setConstraints(Constraint.ON_ANY_NETWORK)
.build();
}
/**
* 2018 September 27 - Thursday - 06:42 PM
* cancel job method
*
* this method will cancel the job USE THIS WHEN YOU DON'T WANT TO USE THE SERVICE ANYMORE.
**/
private void cancelJob(Context context)
{
FirebaseJobDispatcher dispatcher = new FirebaseJobDispatcher(new GooglePlayDriver(context));
//Cancel all the jobs for this package
dispatcher.cancelAll();
// Cancel the job for this tag
dispatcher.cancel("TAGOFTHEJOB");
}