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Android8.0 后台服务保活的一种思路

2022-05-05 14:34 2191 查看 https://www.cnblogs.com/stars-

原文地址:Android8.0 后台服务保活的一种思路 | Stars-One的杂货小窝

项目中有个MQ服务,需要一直连着,接收到消息会发送语音,且手机要在锁屏也要实现此功能

目前是使用广播机制实现,每次MQ收到消息,触发一次启动服务操作逻辑

在Android11版本测试成功,可实现上述功能

步骤

具体流程:

  1. 进入APP
  2. 开启后台服务Service
  3. 后台服务Service开启线程,连接MQ
  4. MQ的消费事件,发送广播
  5. 广播接收器中,处理启动服务(若服务已被关闭)和文本语音播放功能

1.广播注册

<receiver
android:name=".receiver.MyReceiver"
android:enabled="true"
android:exported="true">
</receiver>
public class MyReceiver extends BroadcastReceiver {

@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
//匹配下之前定义的action
if ("OPEN_SERVICE".equals(action)) {
if (!ServiceUtils.isServiceRunning(MqMsgService.class)) {
Log.e("--test", "服务未启动,先启动服务");
Intent myIntent = new Intent(context, MqMsgService.class);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
context.startForegroundService(intent);
} else {
context.startService(intent);
}

}

String text = intent.getStringExtra("text");
Log.e("--test", "广播传的消息"+text);

EventBus.getDefault().post(new SpeakEvent(text));
}
}
}

语音初始化的相关操作都在服务中进行的,这里不再赘述(通过EventBus转发时间事件)

这里需要注意的是,Android8.0版本,广播不能直接

startService()
启动服务,而是要通过
startForegroundService()
方法,而调用了
startForegroundService()
方法,则是需要服务在5s内调用一个方法
startForeground()

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
Notification notification = NotifyUtil.sendNotification(this, "平板", "后台MQ服务运行中", NotificationCompat.PRIORITY_HIGH);
startForeground(1, notification);
}

上面这段代码,就是写在Service中的onCreate方法内,之前也是找到有资料说,需要有通知栏,服务才不会被Android系统给关闭,也不知道有没有起到作用:joy:

还需要注意的是,需要声明权限

<uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
NotifyUtil工具类代码
public class NotifyUtil {
private static String channel_id="myChannelId";
private static String channel_name="新消息";
private static String description = "新消息通知";
private static int notifyId = 0;
private static NotificationManager notificationManager;

public static void createNotificationChannel(){
if (notificationManager != null) {
return;
}
//Android8.0(API26)以上需要调用下列方法,但低版本由于支持库旧,不支持调用
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
int importance = NotificationManager.IMPORTANCE_HIGH;
NotificationChannel channel = new NotificationChannel(channel_id,channel_name,importance);
channel.setDescription(description);
notificationManager = (NotificationManager) ActivityUtils.getTopActivity().getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.createNotificationChannel(channel);
}else{
notificationManager = (NotificationManager) ActivityUtils.getTopActivity().getSystemService(Context.NOTIFICATION_SERVICE);
}
}

public static void sendNotification(String title,String text){
createNotificationChannel();
Notification notification = new NotificationCompat.Builder(ActivityUtils.getTopActivity(),channel_id)
.setContentTitle(title)
.setContentText(text)
.setWhen(System.currentTimeMillis())
.setSmallIcon(ResourceUtils.getMipmapIdByName("ic_launcher"))
.setLargeIcon(BitmapFactory.decodeResource(ActivityUtils.getTopActivity().getResources(), ResourceUtils.getMipmapIdByName("ic_launcher")))
.setPriority(NotificationCompat.PRIORITY_DEFAULT)
.build();
notificationManager.notify(notifyId++,notification);
}

public static Notification sendNotification(Context context,String title,String text,int priority){
createNotificationChannel();
Notification notification = new NotificationCompat.Builder(context,channel_id)
.setContentTitle(title)
.setContentText(text)
.setWhen(System.currentTimeMillis())
.setSmallIcon(ResourceUtils.getMipmapIdByName("ic_launcher"))
.setLargeIcon(BitmapFactory.decodeResource(ActivityUtils.getTopActivity().getResources(), ResourceUtils.getMipmapIdByName("ic_launcher")))
.setPriority(priority)
.build();
notificationManager.notify(notifyId++,notification);
return notification;
}

public static void sendNotification(String title, String text, int priority, PendingIntent pendingIntent){
createNotificationChannel();
Notification notification = new NotificationCompat.Builder(ActivityUtils.getTopActivity(),channel_id)
.setContentTitle(title)
.setContentText(text)
.setWhen(System.currentTimeMillis())
.setSmallIcon(ResourceUtils.getMipmapIdByName("ic_launcher"))
.setLargeIcon(BitmapFactory.decodeResource(ActivityUtils.getTopActivity().getResources(), ResourceUtils.getMipmapIdByName("ic_launcher")))
.setPriority(priority)
.setContentIntent(pendingIntent)
.build();
notificationManager.notify(notifyId++,notification);
}
}

2.服务

声明一个服务,然后在服务中开启一个线程,用来连接MQ,MQ的消费事件中,发送广播

//发出一条广播
String ALARM_ACTION_CODE = "OPEN_SERVICE";
Intent intent = new Intent(ALARM_ACTION_CODE);
//适配8.0以上(不然没法发出广播) 显式声明组件
if (DeviceUtils.getSDKVersionCode() > Build.VERSION_CODES.O) {
intent.setComponent(new ComponentName(context, MyReceiver.class));
}
intent.putExtra("text", msg);
context.sendBroadcast(intent);

之后大体上就是测试了,打开APP,然后直接返回桌面,大概1分钟后,APP就无法播放语音

而使用了上述的思路,不管是锁屏还是回到桌面(测试使用的是Android11,谷歌官方系统),都可以实现语音播放,不过未在其他系统的手机上尝试过

原本现场的设备也就是一个华为平板,而且是鸿蒙系统的

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