最近在做一个埋点的sdk，由于埋点是分批上传的，不是每次都上传，所以会有个进程保活的机制，这也是自研推送的实现技术之一：如何保证Android进程的存活。
对于Android来说，保活主要有以下一些方法：
- 开启前台Service（效果好，推荐）
- Service中循环播放一段无声音频（效果较好，但耗电量高，谨慎使用）
- 双进程守护（Android 5.0前有效）
- JobScheduler（Android 5.0后引入，8.0后失效）
- 1 像素activity保活方案（不推荐）
- 广播锁屏、自定义锁屏（不推荐）
- 第三方推送SDK唤醒（效果好，缺点是第三方接入）
下面是具体的实现方案：
1.监听锁屏广播，开启1个像素的Activity
最早见到这种方案的时候是2015年，有个FM的app为了向投资人展示月活，在Android应用中开启一个1像素的Activity。
由于Activity的级别是比较高的，所以开启1个像素的Activity的方式就可以保证进程是不容易被杀掉的。
具体来说，定义一个1像素的Activity，在该Activity中动态注册自定义的广播。
class OnePixelActivity : AppCompatActivity() {
private lateinit var br: BroadcastReceiver
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
//设定一像素的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
//在一像素activity里注册广播接受者 接受到广播结束掉一像素
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 {
//销毁的时候解锁广播
unregisterReceiver(br)
} catch (e: IllegalArgumentException) {
}
super.onDestroy()
}
/**
* 检查屏幕是否点亮
*/
private fun checkScreenOn() {
val pm = [email protected](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， 双进程守护
双进程守护，在Android 5.0前是有效的，5.0之后就不行了。首先，我们定义定义一个本地服务，在该服务中播放无声音乐，并绑定远程服务
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 {
//播放无声音乐
if (mediaPlayer == null) {
mediaPlayer = MediaPlayer.create(this, R.raw.novioce)
//声音设置为0
mediaPlayer?.setVolume(0f, 0f)
mediaPlayer?.isLooping = true//循环播放
play()
}
//启用前台服务，提升优先级
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)
}
//绑定守护进程
try {
val intent3 = Intent(this, RemoteService::class.java)
this.bindService(intent3, connection, Context.BIND_ABOVE_CLIENT)
} catch (e: Exception) {
}
//隐藏服务通知
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)
[email protected](remoteService)
val intent = Intent(this@LocalService, RemoteService::class.java)
[email protected](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()
}
}
}
然后再定义一个远程服务，绑定本地服务。
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)
[email protected](13691, notification)
}
}
}
private val connection = object : ServiceConnection {
override fun onServiceDisconnected(name: ComponentName) {
val remoteService = Intent(this@RemoteService,
LocalService::class.java)
[email protected](remoteService)
[email protected](Intent(this@RemoteService,
LocalService::class.java), this, Context.BIND_ABOVE_CLIENT)
}
override fun onServiceConnected(name: ComponentName, service: IBinder) {}
}
}
/**
* 通知栏点击广播接受者
*/
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是Android从5.0增加的支持一种特殊的任务调度机制，可以用它来实现进程保活，不过在Android8.0系统中，此种方法也失效。
首先，我们定义一个JobService，开启本地服务和远程服务。
@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) //执行的最小延迟时间
builder.setOverrideDeadline(JobInfo.DEFAULT_INITIAL_BACKOFF_MILLIS) //执行的最长延时时间
builder.setMinimumLatency(JobInfo.DEFAULT_INITIAL_BACKOFF_MILLIS)
builder.setBackoffCriteria(JobInfo.DEFAULT_INITIAL_BACKOFF_MILLIS, JobInfo.BACKOFF_POLICY_LINEAR)//线性重试方案
} else {
builder.setPeriodic(JobInfo.DEFAULT_INITIAL_BACKOFF_MILLIS)
}
builder.setRequiredNetworkType(JobInfo.NETWORK_TYPE_ANY)
builder.setRequiresCharging(true) // 当插入充电器，执行该任务
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)
}
}
//启动本地服务
val localIntent = Intent(context, LocalService::class.java)
//启动守护进程
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，提高Service优先级
在onStartCommand()方法中开启一个通知，提高进程的优先级。注意：从Android 8.0（API级别26）开始，所有通知必须要分配一个渠道，对于每个渠道，可以单独设置视觉和听觉行为。然后用户可以在设置中修改这些设置，根据应用程序来决定哪些通知可以显示或者隐藏。
首先，定义一个通知工具类，此工具栏兼容Android 8.0。
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 这个类型才能传值
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方式
Workmanager是Android JetPac中的一个API，借助Workmanager，我们可以用它来实现应用饿保活。使用前，我们需要依赖Workmanager库，如下：
implementation "android.arch.work:work-runtime:1.0.0-alpha06"
Worker是一个抽象类，用来指定需要执行的具体任务。
public class KeepLiveWork extends Worker {
private static final String TAG = "KeepLiveWork";
@NonNull
@Override
public WorkerResult doWork() {
Log.d(TAG, "keep-> doWork: startKeepService");
//启动job服务
startJobService();
//启动相互绑定的服务
startKeepService();
return WorkerResult.SUCCESS;
}
}
然后，启动keepWork方法，
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);
}
关于WorkManager，可以通过下面的文章来详细了解：WorkManager浅谈
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。