最近在做的项目中需要app在后台常驻，用于实时上传一些健康信息数据，便于后台实时查看用户的健康状况。自从Android7.0以上后台常驻实现越来越难，尤其是8.0及以上。关于保活的文章比比皆是，但是效果并不理想，关于保活的方法也就常说的哪几种，重点在于怎么组合运用。最终实现效果为：用户不主动强制杀死的话，能够一直存活(小米，华为，vivo，oppo，三星)。其中三星s8，华为nova2s用户强制杀死也能存活。
一.项目结构
二.常见的保活方案
关于Android应用保活的文章很多，这里不再阐述，可自行百度。重点在于运用这样方案来实现保活功能。
三.代码实现
1.监听锁屏广播，开启1个像素的Activity。
在锁屏的时候启动一个1个像素的Activity，当用户解锁以后将这个Activity结束掉。
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
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()
}
}
}
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和JobService是安卓在api 21中增加的接口，用于在某些指定条件下执行后台任务。
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.播放无声音乐
这里使用的是有声的mp3文件，只是在代码中把声音设置成了0；如果使用真正的无声的音乐文件，在oppo手机上按下返回键会被立刻杀死，并且在三星手机，华为nova2s强制杀死也会被杀死，所有使用了有声的文件。
5.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。
定义一个通知工具类，兼容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)
}
}
使用
将保活的功能封装成了一个单独的库，依赖该库即可。
app中使用：
KeepLive.startWork(this, KeepLive.RunMode.ROGUE, ForegroundNotification("Title", "message",
R.mipmap.ic_launcher, object : ForegroundNotificationClickListener {
override fun foregroundNotificationClick(context: Context, intent: Intent) {
//点击通知回调
}
}), object : KeepLiveService {
override fun onStop() {
//可能调用多次，跟onWorking匹配调用
}
override fun onWorking() {
//一直存活，可能调用多次
}
})
清单文件配置：
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