十四、Android性能优化之Service

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Service:是一个后台服务,专门用来处理常驻后台的工作组件。

即时通讯:service来做常驻后台

1.核心服务尽可能地轻!

很多人喜欢把所有的后台操作都集中在一个service里面。
为核心服务专门做一个进程,跟其他的所有后台操作隔离。
树大招风,核心服务千万要轻。

进程的重要性优先级:

  • 前台进程:Foreground process

    1.用户正在交互的Activity(onResume())
    2.当某个Service绑定正在交互的Activity
    3.被主动调用为前台的Service(startForeground())
    4.组件正在执行生命周期的回调((onCreate() /onStart()/onDestory())
    5.BroadcastReceiver 正在执行onReceive();

  • 可见进程:Visible process

    1.我们的Activity处在onPause() (没有进入onStop())
    2.绑定到前台Activity的Service

  • 服务进程:Service process

    简单的startservice()启动

  • 后台进程:Background process

    对用户没有直接影响的进程-----Activity处于onStop()的时候

  • 空进程 :Empty process

    不含有任何的活动的组件。(android设计的,为了第二次启动更快,采取了一个权衡)

进程越往后越容易被系统杀死

二、如何提升进程的优先级(尽量做到不轻易被系统杀死)

1.模仿QQ采取在锁屏的时候启动1个像素的Activity。


  背景:当手机锁屏的时候什么都干死了,为了省电。
  监听锁屏广播,锁了---启动这个1像素Activity。
  监听锁屏的,  开启---结束掉这个1像素Activity。
  要监听锁屏的广播---动态注册。

关键代码:


public class KeepLiveActivityManager {
    private static KeepLiveActivityManager instance;
    private Context context;
    private WeakReference<Activity> activityInstance;

    public static KeepLiveActivityManager getInstance(Context context) {
        if(instance==null){
            instance = new KeepLiveActivityManager(context.getApplicationContext());
        }
        return instance;
    }
    
    private KeepLiveActivityManager(Context context) {
        this.context = context;
    }
    
    public void setKeepLiveActivity(Activity activity){
        activityInstance = new WeakReference<Activity>(activity);
    }

    public void startKeepLiveActivity() {
        Intent intent = new  Intent(context, KeepLiveActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(intent);
    }
    public void finishKeepLiveActivity() {
        if(activityInstance!=null&&activityInstance.get()!=null){
            Activity activity = activityInstance.get();
            activity.finish();
        }
    }

}

public class KeepLiveActivity extends Activity {
    private static final String TAG ="KeepLive" ;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

       moveTaskToBack(true); //按home键不退出程序

        Log.i(TAG,"KeepLiveActivity----onCreate");
        Window window = getWindow();
        window.setGravity(Gravity.LEFT|Gravity.TOP);
        WindowManager.LayoutParams params =window.getAttributes();
        params.height = 1;
        params.width  = 1;
        params.x = 0;
        params.y = 0;
        window.setAttributes(params);
        KeepLiveActivityManager.getInstance(this).setKeepLiveActivity(this);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.i(TAG, "KeepLiveActivity----onDestroy!!!");
    }
}

public class MyService extends Service {


    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        ScreenListener listener = new ScreenListener(this);
        listener.begin(new ScreenListener.ScreenStateListener() {
            @Override
            public void onScreenOn() {
                //开屏---finish这个一像素的Activity
                KeepLiveActivityManager.getInstance(MyService.this).finishKeepLiveActivity();
            }

            @Override
            public void onScreenOff() {
                //锁屏---启动一像素的Activity
                KeepLiveActivityManager.getInstance(MyService.this).startKeepLiveActivity();
            }

            @Override
            public void onUserPresent() {

            }
        });

    }
}
源码地址:
KeepLiveProcess

2.大型App运营商和手机厂商可能有合作关系---白名单

3.双进程守护


   一个进程被杀死,另外一个进程又被他启动,相互监听启动。

A<---->B
杀进程是一个一个杀的,本质是和杀进程时间赛跑。
关键代码:


public class LocalService extends Service {

    public static final String ACTION_LOCAL_SERVICE = "com.haocai.app.keepliveprocess.LocalService";
    private static final String TAG = "LocalService";

    private MyServiceConnection conn;
    private MyBinder binder;
    private Intent testIntent;
    @Override
    public void onCreate() {
        // TODO Auto-generated method stub
        super.onCreate();
        if(binder ==null){
            binder = new MyBinder();
        }
        conn = new MyServiceConnection();
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return binder;
    }

    @Override
    public void onDestroy() {
        super.onDestroy();

        if(testIntent!=null){
            stopService(testIntent);
        }

        //unbindService(conn);

    }

    //启动前台进程 增加重要性优先级
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        LocalService.this.bindService(new Intent(LocalService.this, RemoteService.class), conn, Context.BIND_IMPORTANT);

        PendingIntent contentIntent = PendingIntent.getService(this, 0, intent, 0);
        NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
        builder.setTicker("360")
                .setContentIntent(contentIntent)
                .setContentTitle("我是360,我怕谁!")
                .setAutoCancel(true)
                .setContentText("hehehe")
                .setWhen( System.currentTimeMillis());

        //把service设置为前台运行,避免手机系统自动杀掉改服务。
        startForeground(startId, builder.build());
        return START_STICKY;
    }




    class MyBinder extends RemoteConnection.Stub{

        @Override
        public String getProcessName() throws RemoteException {
            // TODO Auto-generated method stub
            return "LocalService";
        }

    }

    class MyServiceConnection implements ServiceConnection {

        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {

            Log.i(TAG, "建立连接成功!");

        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            Log.i(TAG, "本地服务被干掉了~~~~~断开连接!");
            Toast.makeText(LocalService.this, "断开连接", Toast.LENGTH_SHORT).show();
            //启动被干掉的
            testIntent = new Intent();
            //自定义的Service的action
            testIntent.setAction(RemoteService.ACTION_REMOTE_SERVICE);
            //自定义Service的包名
            testIntent.setPackage(getPackageName());
            Log.i("999", getPackageName() + "");
            startService(testIntent);

            LocalService.this.bindService(new Intent(LocalService.this, RemoteService.class), conn, Context.BIND_IMPORTANT);
        }

    }
    }

public class RemoteService  extends Service {

    private static final String TAG = "RemoteService";
    private MyBinder binder;
    private MyServiceConnection conn;
    public static final String ACTION_REMOTE_SERVICE = "com.haocai.app.keepliveprocess.RemoteService";
    private Intent  testIntent;
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return binder;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        if(binder == null){
            binder = new MyBinder();
        }
         conn = new MyServiceConnection();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
//        if(testIntent!=null){
//            stopService(testIntent);
//        }
        //unbindService(conn);

    }

    //启动前台进程 增加重要性优先级
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        RemoteService.this.bindService(new Intent(RemoteService.this, LocalService.class), conn, Context.BIND_IMPORTANT);

        PendingIntent contentIntent = PendingIntent.getService(this, 0, intent, 0);
        NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
        builder.setTicker("360")
                .setContentIntent(contentIntent)
                .setContentTitle("我是360,我怕谁!")
                .setAutoCancel(true)
                .setContentText("hehehe")
                .setWhen( System.currentTimeMillis());

        //把service设置为前台运行,避免手机系统自动杀掉改服务。
        startForeground(startId, builder.build());
        return START_STICKY;
    }


    class  MyBinder extends  RemoteConnection.Stub{

        @Override
        public String getProcessName() throws RemoteException {
            return "RemoteService";
        }
    }

    class MyServiceConnection implements ServiceConnection{
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            Log.i(TAG,"RemoteService 建立连接成功!");
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            Log.i(TAG,"远程服务被干掉了~~~~~断开连接!");
            Toast.makeText(RemoteService.this,"断开连接",Toast.LENGTH_SHORT).show();


            //启动被干掉的
            testIntent = new Intent();
            //自定义的Service的action
            testIntent.setAction(LocalService.ACTION_LOCAL_SERVICE);
            //自定义Service的包名
            testIntent.setPackage(getPackageName());
            Log.i("999",getPackageName()+"");
            startService(testIntent);

            RemoteService.this.bindService(new Intent(RemoteService.this, LocalService.class), conn, Context.BIND_IMPORTANT);
        }
        }

    }
源码地址:
KeepLiveProcess2

4.JobScheduler

把任务加到系统调度队列中,当到达任务窗口期的时候就会执行,我们可以在这个任务里面启动我们的进程。
这样可以做到将近杀不死的进程。


@SuppressLint("NewApi")
public class JobHandleService extends JobService{
    public static final String ACTION_JOB_HANDLE_SERVICE = "com.haocai.app.keepliveprocess.JobHandleService";
    private int kJobId = 0;
    @Override
    public void onCreate() {
        super.onCreate();
        Log.i("INFO", "jobService create");

    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.i("INFO", "jobService start");
        scheduleJob(getJobInfo());
        return START_NOT_STICKY;
    }

    @Override
    public void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
    }

    @Override
    public boolean onStartJob(JobParameters params) {
        // TODO Auto-generated method stub
        Log.i("INFO", "job start");
//      scheduleJob(getJobInfo());
        boolean isLocalServiceWork = isServiceWork(this, LocalService.ACTION_LOCAL_SERVICE);
        boolean isRemoteServiceWork = isServiceWork(this, RemoteService.ACTION_REMOTE_SERVICE);
//      Log.i("INFO", "localSericeWork:"+isLocalServiceWork);
//      Log.i("INFO", "remoteSericeWork:"+isRemoteServiceWork);
        if(!isLocalServiceWork||
                !isRemoteServiceWork){
            //this.startService(new Intent(this,LocalService.class));
            startLocalService();
            startRemoteService();
            //this.startService(new Intent(this,RemoteService.class));
            Toast.makeText(this, "process start", Toast.LENGTH_SHORT).show();
        }
        return true;
    }


    private void startLocalService(){
        Intent  testIntent = new Intent();

        //自定义的Service的action
        testIntent.setAction(LocalService.ACTION_LOCAL_SERVICE);
        //自定义Service的包名
        testIntent.setPackage(getPackageName());
        Log.i("999",getPackageName()+"");
        startService(testIntent);
    }
    private void  startRemoteService(){
        Intent testIntent = new Intent();

        //自定义的Service的action
        testIntent.setAction(RemoteService.ACTION_REMOTE_SERVICE);
        //自定义Service的包名
        testIntent.setPackage(getPackageName());
        Log.i("999", getPackageName() + "");
        startService(testIntent);

    }

    @Override
    public boolean onStopJob(JobParameters params) {
        Log.i("INFO", "job stop");
//      Toast.makeText(this, "process stop", Toast.LENGTH_SHORT).show();
        scheduleJob(getJobInfo());
        return true;
    }

    /** Send job to the JobScheduler. */
    public void scheduleJob(JobInfo t) {
        Log.i("INFO", "Scheduling job");
        JobScheduler tm =
                (JobScheduler) getSystemService(Context.JOB_SCHEDULER_SERVICE);
        tm.schedule(t);
    }

    public JobInfo getJobInfo(){
        JobInfo.Builder builder = new JobInfo.Builder(kJobId++, new ComponentName(this, JobHandleService.class));
        builder.setRequiredNetworkType(JobInfo.NETWORK_TYPE_ANY);
        builder.setPersisted(true);
        builder.setRequiresCharging(false);
        builder.setRequiresDeviceIdle(false);
        builder.setPeriodic(10);//间隔时间--周期
        return builder.build();
    }


    /**
     * 判断某个服务是否正在运行的方法
     *
     * @param mContext
     * @param serviceName
     *            是包名+服务的类名(例如:net.loonggg.testbackstage.TestService)
     * @return true代表正在运行,false代表服务没有正在运行
     */
    public boolean isServiceWork(Context mContext, String serviceName) {
        boolean isWork = false;
        ActivityManager myAM = (ActivityManager) mContext
                .getSystemService(Context.ACTIVITY_SERVICE);
        List<RunningServiceInfo> myList = myAM.getRunningServices(100);
        if (myList.size() <= 0) {
            return false;
        }
        for (int i = 0; i < myList.size(); i++) {
            String mName = myList.get(i).service.getClassName().toString();
            if (mName.equals(serviceName)) {
                isWork = true;
                break;
            }
        }
        return isWork;
    }
}

      <service
            android:name=".JobHandleService"
            android:permission="android.permission.BIND_JOB_SERVICE">
        </service>

5.监听QQ,微信,系统应用,友盟,小米推送等等的广播,然后把自己启动了。

6.利用账号同步机制唤醒我们的进程

AccountManager

7.NDK来解决,Native进程来实现双进程守护。