Android实现crontab

crontab在Android中并不支持，即使是撞了busybox之后

需要借用AlarmManager，在指定的时间唤醒某个task

需求是：

1. 随机启动某个service

2. service启动后检测某个系统指标，或者周期性运行某个任务

1. 随机启动service

public class AutoStartBroadCastReceiver extends BroadcastReceiver {

    private String TAG = AutoSignService.class.getName();

    @Override

    public void onReceive(Context arg0, Intent arg1) {

        // TODO Auto-generated method stub

        Log.e(TAG, "AutoStartBroadCastReceiver onCreate");

        Intent intent = new Intent(arg0, AutoSignService.class);

        arg0.startService(intent);

    }

}

AndroidManifest.xml

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

2. service启动，借用PendingIntent.getBroadcast发送广播，广播接收者做实际的检测某个系统指标，或者周期性运行某个任务

public class AutoSignService extends Service {

    private String TAG = AutoSignService.class.getName();

    AlarmManager mAlarmManager;

    Intent workIntent;

    PendingIntent mPendingIntent;

    SignTimzBroadcastReceiver mSignTimzBroadcastReceiver;

    @Override

    public IBinder onBind(Intent arg0) {

        // TODO Auto-generated method stub

        return null;

    }

    @Override

    public void onCreate()

    {

        Log.e(TAG, "onCreate");

        mAlarmManager = (AlarmManager)this.getSystemService(Context.ALARM_SERVICE);

        workIntent = new Intent();

        mSignTimzBroadcastReceiver = new SignTimzBroadcastReceiver();

        IntentFilter signTimzIntentFilter = new IntentFilter();

        signTimzIntentFilter.addAction("com.run.sign.timz");

        registerReceiver(mSignTimzBroadcastReceiver, signTimzIntentFilter);

    }

    @Override

    public int onStartCommand(android.content.Intent intent, int flags, int startId)

    {

        Log.e(TAG, "onStartCommand");

        workIntent.setAction("com.run.sign.timz");

        mPendingIntent = PendingIntent.getBroadcast(AutoSignService.this, 0, workIntent, 0);

        Calendar calendar = Calendar.getInstance();

        calendar.setTimeInMillis(System.currentTimeMillis());

        calendar.add(Calendar.SECOND, 10);

        mAlarmManager.setRepeating(AlarmManager.RTC_WAKEUP, 

                calendar.getTimeInMillis(), 

                1000, 

                mPendingIntent);

        return 0;

    }

    @Override

    public void onDestroy()

    {

        Log.e(TAG, "onDestroy");

        this.unregisterReceiver(mSignTimzBroadcastReceiver);

    }

    class SignTimzBroadcastReceiver extends BroadcastReceiver

    {

        @Override

        public void onReceive(Context arg0, Intent arg1) {

            // TODO Auto-generated method stub

            Log.e(TAG, "SignTimzBroadcastReceiver Runtime");

            suShell("uiautomator runtest UIAutomatorTest.jar");

        }

        //需要root权限执行命令时使用该方法

        public void suShell(String cmd) {

            Process ps = null;

            DataOutputStream os;

            try {

//                ps = Runtime.getRuntime().exec("su");

//                os = new DataOutputStream(ps.getOutputStream());

//                

//                os.writeBytes(cmd + "\n");

//                os.writeBytes("exit\n");

//                os.flush();

                Runtime.getRuntime().exec(cmd);

            } catch (IOException e) {

                e.printStackTrace();

            }

        }

    }

}