性能优化二十三之Service进程防杀死

前言

        Service作为四大组件之一很多安卓开发者对他肯定是又爱又恨，爱在它可以帮助我们去处理常驻后台的任务操作，比如说推送服务，心跳传输等，恨在当Servcie遇到360、腾讯管家之类的杀毒软件，变得脆弱，很容易被杀死，或者当用户手机锁屏会导致服务暂时停止运行。
        我们常用的进程守护的套路无外乎以下几种:
一、提高进程的优先级数值
        对于Service被系统回收，一般做法是通过提高优先级可以解决，在AndroidManifest.xml文件中对于intent-filter可以通过Android:priority = “1000”这个属性设置最高优先级，1000是最高值，如果数字越小则优先级越低。
二、改变进程等级

进程的重要性优先级：（越往后的就越容易被系统杀死）
1.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Service（startForeground()）
    4）组件正在执行生命周期的回调（onCreate()/onStart()/onDestroy()）
    5）BroadcastReceiver 正在执行onReceive();

2.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。

3.服务进程；Service process
    简单的startService()启动。
4.后台进程；Background process
    对用户没有直接影响的进程----Activity出于onStop()的时候。
    android:process=":xxx"
5.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，采取的一个权衡）

三、设置 android:persistent属性为true

< application 
    android:name="com.test.Application" 
    android:allowBackup="true" 
    android:icon="@drawable/ic_launcher" 
    android:label="@string/app_name" 
    android:persistent="true"</span> 
    android:theme="@style/AppTheme" > 
< /application> 

        这个属性设置后，的确发现优先级提高不少，或许是相当于系统级的进程，但是还是无法保证存活。

四、onDestory方法内调用广播，重启Service
当service执行了onDestory的时候，发送一个自定义的广播，当收到广播的时候，重新启动service。

<receiver android:name="com.dbjtech.acbxt.waiqin.BootReceiver" >  
    <intent-filter>  
        <action android:name="android.intent.action.BOOT_COMPLETED" />  
        <action android:name="android.intent.action.USER_PRESENT" />  
        <action android:name="com.dbjtech.waiqin.destroy" />//这个就是自定义的action  
    </intent-filter>  
</receiver>  

@Override  
public void onDestroy() {  
    stopForeground(true);  
    Intent intent = new Intent("com.dbjtech.waiqin.destroy");  
    sendBroadcast(intent);  
    super.onDestroy();  
}  

public class BootReceiver extends BroadcastReceiver {  

    @Override  
    public void onReceive(Context context, Intent intent) {  
        if (intent.getAction().equals("com.dbjtech.waiqin.destroy")) {  
            //TODO  
            //在这里写重新启动service的相关操作  
                startUploadService(context);  
        }  

    }  

}  

        但是当使用类似于360卫士和腾讯管家等第三方应用或是在setting里-应用-强制停止时，APP进程可能就直接被干掉了，onDestroy方法都进不来，所以还是无法保证存活。
五、监听系统广播判断Service状态
通过系统的一些广播，比如：手机重启、界面唤醒、应用状态改变等等监听并捕获到，然后判断我们的Service是否还存活，记得加权限

<receiver android:name="com.dbjtech.acbxt.waiqin.BootReceiver" > 
    <intent-filter> 
        <action android:name="android.intent.action.BOOT_COMPLETED" /> 
        <action android:name="android.intent.action.USER_PRESENT" /> 
        <action android:name="android.intent.action.PACKAGE_RESTARTED" /> 
        <action android:name="com.dbjtech.waiqin.destroy" /> 
    </intent-filter> 
</receiver> 

在BroadcastReceiver中：

@Override 
public void onReceive(Context context, Intent intent) { 
    if (Intent.ACTION_BOOT_COMPLETED.equals(intent.getAction())) { 
        System.out.println("手机开机了...."); 
        startUploadService(context); 
    } 
    if (Intent.ACTION_USER_PRESENT.equals(intent.getAction())) { 
            startUploadService(context); 
    } 
} 

        这个方法监听多了会导致Service很混乱，带来诸多麻烦。

六、QQ采取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（顺便同时把自己的核心服务再开启一次,接下来就来模拟实现：

//主界面Activity
public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Intent intent = new Intent(this, MyService.class);
        startService(intent);
    }

    public void jump(View v){
        Intent intent = new Intent(this, KeepLiveActivity.class);
        startActivity(intent);
        finish();
    }
}

//1个像素的activity
public class KeepLiveActivity extends Activity {
    private static final String TAG = "kiven";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
//      setContentView(R.layout.activity_main);
        Log.i(TAG, "KeepLiveActivity----onCreate!!!");
        Window window = getWindow();
        window.setGravity(Gravity.LEFT|Gravity.TOP);
        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() {
        // TODO Auto-generated method stub
        super.onDestroy();
        Log.i(TAG, "KeepLiveActivity----onDestroy!!!");
    }   
}

//管理服务的开启与关闭
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();
        }
    }

}

//屏幕状态监听
public class ScreenListener {
    private Context mContext;
    private ScreenBroadcastReceiver mScreenReceiver;
    private ScreenStateListener mScreenStateListener;

    public ScreenListener(Context context) {
        mContext = context;
        mScreenReceiver = new ScreenBroadcastReceiver();
    }

    /**
     * screen状态广播接收者
     */
    private class ScreenBroadcastReceiver extends BroadcastReceiver {
        private String action = null;
        @Override
        public void onReceive(Context context, Intent intent) {
            action = intent.getAction();
            if (Intent.ACTION_SCREEN_ON.equals(action)) { // 开屏
                mScreenStateListener.onScreenOn();
            } else if (Intent.ACTION_SCREEN_OFF.equals(action)) { // 锁屏
                mScreenStateListener.onScreenOff();
            } else if (Intent.ACTION_USER_PRESENT.equals(action)) { // 解锁
                mScreenStateListener.onUserPresent();
            }
        }
    }

    /**
     * 开始监听screen状态
     * 
     * @param listener
     */
    public void begin(ScreenStateListener listener) {
        mScreenStateListener = listener;
        registerListener();
        getScreenState();
    }

    /**
     * 获取screen状态
     */
    private void getScreenState() {
        PowerManager manager = (PowerManager) mContext
                .getSystemService(Context.POWER_SERVICE);
        if (manager.isScreenOn()) {
            if (mScreenStateListener != null) {
                mScreenStateListener.onScreenOn();
            }
        } else {
            if (mScreenStateListener != null) {
                mScreenStateListener.onScreenOff();
            }
        }
    }

    /**
     * 停止screen状态监听
     */
    public void unregisterListener() {
        mContext.unregisterReceiver(mScreenReceiver);
    }

    /**
     * 启动screen状态广播接收器
     */
    private void registerListener() {
        IntentFilter filter = new IntentFilter();
        filter.addAction(Intent.ACTION_SCREEN_ON);
        filter.addAction(Intent.ACTION_SCREEN_OFF);
        filter.addAction(Intent.ACTION_USER_PRESENT);
        mContext.registerReceiver(mScreenReceiver, filter);
    }

    public interface ScreenStateListener {// 返回给调用者屏幕状态信息
        public void onScreenOn();

        public void onScreenOff();

        public void onUserPresent();
    }


    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
    <uses-permission android:name="android.permission.RECEIVE_USER_PRESENT"/>
}

        上面实现了1像素保活，当接受到监听锁屏广播，就会启动这个1个像素的Activity，当监听界面唤醒广播，就结束掉这个1个像素的Activity，要监听锁屏的广播需要使用动态注册的方式(实际项目中不会出现静态注册广播的方式)。
七：双进程守护(重点)
        如何让系统或者第三方应用无法杀死进程，除了上面的六种方式，还有的就是一般手机厂商会与app运营商达成合作，加入到白名单，就不会被杀死。这种方式我们一般是很难用的。但是另一种方式双进程守护方式来实现，什么是双进程守护？双进程守护—可以防止单个进程杀死，同时可以防止第三方的360清理掉。一个进程被杀死，另外一个进程又被他启动。相互监听启动。双进程的互相唤醒，就相当于双进程之间要进行互相通信，进程间的通信是通过binder机制，所以这两个进程之间可以通过aidl来实现。

RemoteConnection.aidl
interface RemoteConnection{
    String getProcessName();
}

LocalService.java 本地服务
public class LocalService extends Service {

    public static final String TAG = "kiven";
    private MyBinder binder;
    private MyServiceConnection conn;

    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return binder;
    }

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

    @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")
        .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, "RemoteService服务被干掉了~~~~断开连接！");
            Toast.makeText(LocalService.this, "断开连接", 0).show();
            //启动被干掉的
            LocalService.this.startService(new Intent(LocalService.this, RemoteService.class));
            LocalService.this.bindService(new Intent(LocalService.this, RemoteService.class), conn, Context.BIND_IMPORTANT);
        }   
    }
}

RemoteService.java: 远程服务（另一个进程）
public class RemoteService extends Service {

    public static final String TAG = "kiven";
    private MyBinder binder;
    private MyServiceConnection conn;

    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return binder;
    }

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

    @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")
        .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, "LocalService服务被干掉了~~~~断开连接！");
            Toast.makeText(RemoteService.this, "断开连接", 0).show();
            //启动被干掉的
            RemoteService.this.startService(new Intent(RemoteService.this, LocalService.class));
            RemoteService.this.bindService(new Intent(RemoteService.this, LocalService.class), conn, Context.BIND_IMPORTANT);
        }   
    }
}


MainActivity.java:
public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        startService(new Intent(this, LocalService.class));
        startService(new Intent(this, RemoteService.class));
        startService(new Intent(this, JobHandleService.class));
    }

}

JobHandleService.java: JobHandlerService的作用是为了防止应用被强制关闭导致服务被杀（实际开发不建议使用，太流氓了）
@SuppressLint("NewApi")
public class JobHandleService extends JobService{
    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, "com.kiven.keepliveprocess.LocalService");
        boolean isRemoteServiceWork = isServiceWork(this, "com.kiven.keepliveprocess.RemoteService");
//      Log.i("INFO", "localSericeWork:"+isLocalServiceWork);
//      Log.i("INFO", "remoteSericeWork:"+isRemoteServiceWork);
        if(!isLocalServiceWork||
           !isRemoteServiceWork){
            this.startService(new Intent(this,LocalService.class));
            this.startService(new Intent(this,RemoteService.class));
            Toast.makeText(this, "process start", Toast.LENGTH_SHORT).show();
        }
        return true;
    }

    @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;  
    }  
}

AndroidManifest.xml:
....    
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
...

   <service android:name="com.kiven.keepliveprocess.LocalService"></service>
   <service 
        android:name="com.kiven.keepliveprocess.RemoteService"
        android:process=":remoteprocess"
       ></service>
    <service android:name="com.kiven.keepliveprocess.JobHandleService" android:permission="android.permission.BIND_JOB_SERVICE"></service>
    </application>

</manifest>

       至此，进程保活的方式介绍完毕，实际上进程保护有很多种方式，需要根据实际的需求去选择适合的方式，一个小建议:不要把app搞的太”流氓”，会导致用户手机用电量飙升，CPU发热，也对用户的体验不好。