Explain in detail how to keep alive the application of Android 8.0 and above systems
- 2021-11-13 02:39:12
- OfStack
Recently, I am doing an sdk with a buried point. Because the buried points are uploaded in batches, not every time, there will be a mechanism to keep the process alive, which is also the first implementation technology of self-developed push: how to ensure the survival of Android process.
For Android, there are mainly the following methods to keep alive:
Open the foreground Service (good effect, recommended) Loop 1 silent audio in Service (good effect, but high power consumption, use carefully) Dual process daemon (valid until Android 5.0) JobScheduler (Android introduced after 5.0, failed after 8.0) 1-Pixel activity Keep Alive Scheme (Not Recommended) Broadcast Lock Screen, Custom Lock Screen (Not Recommended) The third party pushes SDK wake-up (the effect is good, but the disadvantage is that the third party accesses)The following is the specific implementation scheme:
1. Listen to the lock screen broadcast and turn on Activity with 1 pixel
The first time I saw this scheme was in 2015. In order to show investors the monthly activity, an app of FM started a 1-pixel Activity in the Android application.
Because the level of Activity is relatively high, turning on Activity with 1 pixel can ensure that the process is not easy to be killed.
Specifically, define a 1-pixel Activity, and dynamically register custom broadcasts in this Activity.
class OnePixelActivity : AppCompatActivity() {
private lateinit var br: BroadcastReceiver
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
// Setting 1 Pixel activity
val window = window
window.setGravity(Gravity.LEFT or Gravity.TOP)
val params = window.attributes
params.x = 0
params.y = 0
params.height = 1
params.width = 1
window.attributes = params
// In 1 Pixel activity Registered broadcast recipients in Accept it until the broadcast is over 1 Pixel
br = object : BroadcastReceiver() {
override fun onReceive(context: Context, intent: Intent) {
finish()
}
}
registerReceiver(br, IntentFilter("finish activity"))
checkScreenOn()
}
override fun onResume() {
super.onResume()
checkScreenOn()
}
override fun onDestroy() {
try {
// Unlock the broadcast when destroying
unregisterReceiver(br)
} catch (e: IllegalArgumentException) {
}
super.onDestroy()
}
/**
* Check whether the screen lights up
*/
private fun checkScreenOn() {
val pm = this@OnePixelActivity.getSystemService(Context.POWER_SERVICE) as PowerManager
val isScreenOn = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT_WATCH) {
pm.isInteractive
} else {
pm.isScreenOn
}
if (isScreenOn) {
finish()
}
}
}
2. Double process guardian
Dual process daemon, effective before Android 5.0, not after 5.0. First, we define a local service, play silent music in this service, and bind the remote service
class LocalService : Service() {
private var mediaPlayer: MediaPlayer? = null
private var mBilder: MyBilder? = null
override fun onCreate() {
super.onCreate()
if (mBilder == null) {
mBilder = MyBilder()
}
}
override fun onBind(intent: Intent): IBinder? {
return mBilder
}
override fun onStartCommand(intent: Intent, flags: Int, startId: Int): Int {
// Play silent music
if (mediaPlayer == null) {
mediaPlayer = MediaPlayer.create(this, R.raw.novioce)
// Sound set to 0
mediaPlayer?.setVolume(0f, 0f)
mediaPlayer?.isLooping = true// Loop playback
play()
}
// Enable foreground service and raise priority
if (KeepLive.foregroundNotification != null) {
val intent2 = Intent(applicationContext, NotificationClickReceiver::class.java)
intent2.action = NotificationClickReceiver.CLICK_NOTIFICATION
val notification = NotificationUtils.createNotification(this, KeepLive.foregroundNotification!!.getTitle(), KeepLive.foregroundNotification!!.getDescription(), KeepLive.foregroundNotification!!.getIconRes(), intent2)
startForeground(13691, notification)
}
// Binding daemon
try {
val intent3 = Intent(this, RemoteService::class.java)
this.bindService(intent3, connection, Context.BIND_ABOVE_CLIENT)
} catch (e: Exception) {
}
// Hide service notifications
try {
if (Build.VERSION.SDK_INT < 25) {
startService(Intent(this, HideForegroundService::class.java))
}
} catch (e: Exception) {
}
if (KeepLive.keepLiveService != null) {
KeepLive.keepLiveService!!.onWorking()
}
return Service.START_STICKY
}
private fun play() {
if (mediaPlayer != null && !mediaPlayer!!.isPlaying) {
mediaPlayer?.start()
}
}
private inner class MyBilder : GuardAidl.Stub() {
@Throws(RemoteException::class)
override fun wakeUp(title: String, discription: String, iconRes: Int) {
}
}
private val connection = object : ServiceConnection {
override fun onServiceDisconnected(name: ComponentName) {
val remoteService = Intent(this@LocalService,
RemoteService::class.java)
this@LocalService.startService(remoteService)
val intent = Intent(this@LocalService, RemoteService::class.java)
this@LocalService.bindService(intent, this,
Context.BIND_ABOVE_CLIENT)
}
override fun onServiceConnected(name: ComponentName, service: IBinder) {
try {
if (mBilder != null && KeepLive.foregroundNotification != null) {
val guardAidl = GuardAidl.Stub.asInterface(service)
guardAidl.wakeUp(KeepLive.foregroundNotification?.getTitle(), KeepLive.foregroundNotification?.getDescription(), KeepLive.foregroundNotification!!.getIconRes())
}
} catch (e: RemoteException) {
e.printStackTrace()
}
}
}
override fun onDestroy() {
super.onDestroy()
unbindService(connection)
if (KeepLive.keepLiveService != null) {
KeepLive.keepLiveService?.onStop()
}
}
}Then define a remote service and bind the local service.
class RemoteService : Service() {
private var mBilder: MyBilder? = null
override fun onCreate() {
super.onCreate()
if (mBilder == null) {
mBilder = MyBilder()
}
}
override fun onBind(intent: Intent): IBinder? {
return mBilder
}
override fun onStartCommand(intent: Intent, flags: Int, startId: Int): Int {
try {
this.bindService(Intent(this@RemoteService, LocalService::class.java),
connection, Context.BIND_ABOVE_CLIENT)
} catch (e: Exception) {
}
return Service.START_STICKY
}
override fun onDestroy() {
super.onDestroy()
unbindService(connection)
}
private inner class MyBilder : GuardAidl.Stub() {
@Throws(RemoteException::class)
override fun wakeUp(title: String, discription: String, iconRes: Int) {
if (Build.VERSION.SDK_INT < 25) {
val intent = Intent(applicationContext, NotificationClickReceiver::class.java)
intent.action = NotificationClickReceiver.CLICK_NOTIFICATION
val notification = NotificationUtils.createNotification(this@RemoteService, title, discription, iconRes, intent)
this@RemoteService.startForeground(13691, notification)
}
}
}
private val connection = object : ServiceConnection {
override fun onServiceDisconnected(name: ComponentName) {
val remoteService = Intent(this@RemoteService,
LocalService::class.java)
this@RemoteService.startService(remoteService)
this@RemoteService.bindService(Intent(this@RemoteService,
LocalService::class.java), this, Context.BIND_ABOVE_CLIENT)
}
override fun onServiceConnected(name: ComponentName, service: IBinder) {}
}
}
/**
* Click on the broadcast recipient in the notification bar
*/
class NotificationClickReceiver : BroadcastReceiver() {
companion object {
const val CLICK_NOTIFICATION = "CLICK_NOTIFICATION"
}
override fun onReceive(context: Context, intent: Intent) {
if (intent.action == NotificationClickReceiver.CLICK_NOTIFICATION) {
if (KeepLive.foregroundNotification != null) {
if (KeepLive.foregroundNotification!!.getForegroundNotificationClickListener() != null) {
KeepLive.foregroundNotification!!.getForegroundNotificationClickListener()?.foregroundNotificationClick(context, intent)
}
}
}
}
}
3. JobScheduler
JobScheduler is a special task scheduling mechanism added from Android 5.0, which can be used to keep process alive, but this method also fails in Android 8.0 system.
First, we define an JobService to start local service and remote service.
@SuppressWarnings(value = ["unchecked", "deprecation"])
@RequiresApi(Build.VERSION_CODES.LOLLIPOP)
class JobHandlerService : JobService() {
private var mJobScheduler: JobScheduler? = null
override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
var startId = startId
startService(this)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
mJobScheduler = getSystemService(Context.JOB_SCHEDULER_SERVICE) as JobScheduler
val builder = JobInfo.Builder(startId++,
ComponentName(packageName, JobHandlerService::class.java.name))
if (Build.VERSION.SDK_INT >= 24) {
builder.setMinimumLatency(JobInfo.DEFAULT_INITIAL_BACKOFF_MILLIS) // Minimum delay time for execution
builder.setOverrideDeadline(JobInfo.DEFAULT_INITIAL_BACKOFF_MILLIS) // Maximum delay time of execution
builder.setMinimumLatency(JobInfo.DEFAULT_INITIAL_BACKOFF_MILLIS)
builder.setBackoffCriteria(JobInfo.DEFAULT_INITIAL_BACKOFF_MILLIS, JobInfo.BACKOFF_POLICY_LINEAR)// Linear retry scheme
} else {
builder.setPeriodic(JobInfo.DEFAULT_INITIAL_BACKOFF_MILLIS)
}
builder.setRequiredNetworkType(JobInfo.NETWORK_TYPE_ANY)
builder.setRequiresCharging(true) // When the charger is plugged in, perform this task
mJobScheduler?.schedule(builder.build())
}
return Service.START_STICKY
}
private fun startService(context: Context) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
if (KeepLive.foregroundNotification != null) {
val intent = Intent(applicationContext, NotificationClickReceiver::class.java)
intent.action = NotificationClickReceiver.CLICK_NOTIFICATION
val notification = NotificationUtils.createNotification(this, KeepLive.foregroundNotification!!.getTitle(), KeepLive.foregroundNotification!!.getDescription(), KeepLive.foregroundNotification!!.getIconRes(), intent)
startForeground(13691, notification)
}
}
// Start local service
val localIntent = Intent(context, LocalService::class.java)
// Start the daemon
val guardIntent = Intent(context, RemoteService::class.java)
startService(localIntent)
startService(guardIntent)
}
override fun onStartJob(jobParameters: JobParameters): Boolean {
if (!isServiceRunning(applicationContext, "com.xiyang51.keeplive.service.LocalService") || !isServiceRunning(applicationContext, "$packageName:remote")) {
startService(this)
}
return false
}
override fun onStopJob(jobParameters: JobParameters): Boolean {
if (!isServiceRunning(applicationContext, "com.xiyang51.keeplive.service.LocalService") || !isServiceRunning(applicationContext, "$packageName:remote")) {
startService(this)
}
return false
}
private fun isServiceRunning(ctx: Context, className: String): Boolean {
var isRunning = false
val activityManager = ctx
.getSystemService(Context.ACTIVITY_SERVICE) as ActivityManager
val servicesList = activityManager
.getRunningServices(Integer.MAX_VALUE)
val l = servicesList.iterator()
while (l.hasNext()) {
val si = l.next()
if (className == si.service.className) {
isRunning = true
}
}
return isRunning
}
}
4. Improve the priority of Service
Turn on a notification in the onStartCommand () method to increase the priority of the process. Note: Beginning with Android 8.0 (API level 26), all notifications must be assigned 1 channel, and visual and auditory behaviors can be set separately for each channel. The user can then modify these settings in the settings, depending on the application to decide which notifications can be displayed or hidden.
First, define a notification tool class, which is Android 8.0 compliant.
class NotificationUtils(context: Context) : ContextWrapper(context) {
private var manager: NotificationManager? = null
private var id: String = context.packageName + "51"
private var name: String = context.packageName
private var context: Context = context
private var channel: NotificationChannel? = null
companion object {
@SuppressLint("StaticFieldLeak")
private var notificationUtils: NotificationUtils? = null
fun createNotification(context: Context, title: String, content: String, icon: Int, intent: Intent): Notification? {
if (notificationUtils == null) {
notificationUtils = NotificationUtils(context)
}
var notification: Notification? = null
notification = if (Build.VERSION.SDK_INT >= 26) {
notificationUtils?.createNotificationChannel()
notificationUtils?.getChannelNotification(title, content, icon, intent)?.build()
} else {
notificationUtils?.getNotification_25(title, content, icon, intent)?.build()
}
return notification
}
}
@RequiresApi(api = Build.VERSION_CODES.O)
fun createNotificationChannel() {
if (channel == null) {
channel = NotificationChannel(id, name, NotificationManager.IMPORTANCE_MIN)
channel?.enableLights(false)
channel?.enableVibration(false)
channel?.vibrationPattern = longArrayOf(0)
channel?.setSound(null, null)
getManager().createNotificationChannel(channel)
}
}
private fun getManager(): NotificationManager {
if (manager == null) {
manager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
}
return manager!!
}
@RequiresApi(api = Build.VERSION_CODES.O)
fun getChannelNotification(title: String, content: String, icon: Int, intent: Intent): Notification.Builder {
//PendingIntent.FLAG_UPDATE_CURRENT This type can pass values
val pendingIntent = PendingIntent.getBroadcast(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT)
return Notification.Builder(context, id)
.setContentTitle(title)
.setContentText(content)
.setSmallIcon(icon)
.setAutoCancel(true)
.setContentIntent(pendingIntent)
}
fun getNotification_25(title: String, content: String, icon: Int, intent: Intent): NotificationCompat.Builder {
val pendingIntent = PendingIntent.getBroadcast(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT)
return NotificationCompat.Builder(context, id)
.setContentTitle(title)
.setContentText(content)
.setSmallIcon(icon)
.setAutoCancel(true)
.setVibrate(longArrayOf(0))
.setSound(null)
.setLights(0, 0, 0)
.setContentIntent(pendingIntent)
}
}
5. Workmanager mode
Workmanager is an API in Android JetPac. With the help of Workmanager, we can use it to keep alive. Before using it, we need to rely on the Workmanager library, as follows:
implementation "android.arch.work:work-runtime:1.0.0-alpha06"
Worker is an abstract class that specifies specific tasks that need to be performed.
public class KeepLiveWork extends Worker {
private static final String TAG = "KeepLiveWork";
@NonNull
@Override
public WorkerResult doWork() {
Log.d(TAG, "keep-> doWork: startKeepService");
// Start job Services
startJobService();
// Start services bound to each other
startKeepService();
return WorkerResult.SUCCESS;
}
}
Then, start the keepWork method,
public void startKeepWork() {
WorkManager.getInstance().cancelAllWorkByTag(TAG_KEEP_WORK);
Log.d(TAG, "keep-> dowork startKeepWork");
OneTimeWorkRequest oneTimeWorkRequest = new OneTimeWorkRequest.Builder(KeepLiveWork.class)
.setBackoffCriteria(BackoffPolicy.LINEAR, 5, TimeUnit.SECONDS)
.addTag(TAG_KEEP_WORK)
.build();
WorkManager.getInstance().enqueue(oneTimeWorkRequest);
}
About WorkManager, you can learn more about it through the following article: Talking about WorkManager