Android系统实现记录用户的开关机数据，获取某段时间内的用户开机率，并且将开关机数据以及用户开机率保存到日志文件中

Android系统提供了相应的API来获取设备的开关机数据，可以通过BroadcastReceiver接收设备开关机的广播，并在接收到广播时记录相应的数据。以下是一个示例代码：

public class BootReceiver extends BroadcastReceiver {
    private static final String TAG = "BootReceiver";

    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent == null) {
            return;
        }
        String action = intent.getAction();
        if (action == null) {
            return;
        }
        switch (action) {
            case Intent.ACTION_BOOT_COMPLETED:
                // 设备开机
                Log.i(TAG, "Boot completed");
                saveBootData(context, true);
                break;
            case Intent.ACTION_SHUTDOWN:
                // 设备关机
                Log.i(TAG, "Shutdown");
                saveBootData(context, false);
                break;
        }
    }

    private void saveBootData(Context context, boolean isBoot) {
        SharedPreferences sp = context.getSharedPreferences("boot_data", Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sp.edit();
        String key = new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault()).format(new Date());
        int bootCount = sp.getInt(key + "_boot_count", 0);
        int shutdownCount = sp.getInt(key + "_shutdown_count", 0);
        if (isBoot) {
            bootCount++;
        } else {
            shutdownCount++;
        }
        editor.putInt(key + "_boot_count", bootCount);
        editor.putInt(key + "_shutdown_count", shutdownCount);
        editor.apply();
    }
}

可以在AndroidManifest.xml中注册该BroadcastReceiver：

<receiver android:name=".BootReceiver">
    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED" />
        <action android:name="android.intent.action.SHUTDOWN" />
    </intent-filter>
</receiver>

可以使用JobScheduler或AlarmManager定时获取某段时间内的用户开机率，以下是一个示例代码：

public class BootJobService extends JobService {
    private static final String TAG = "BootJobService";
    private static final int JOB_ID = 1001;
    private static final long INTERVAL = 24 * 60 * 60 * 1000; // 一天

    @Override
    public boolean onStartJob(JobParameters params) {
        Log.i(TAG, "onStartJob");
        getBootRate(getApplicationContext());
        scheduleNextJob();
        return false;
    }

    @Override
    public boolean onStopJob(JobParameters params) {
        Log.i(TAG, "onStopJob");
        return false;
    }

    private void scheduleNextJob() {
        JobScheduler jobScheduler = (JobScheduler) getSystemService(Context.JOB_SCHEDULER_SERVICE);
        if (jobScheduler == null) {
            return;
        }
        JobInfo jobInfo = new JobInfo.Builder(JOB_ID, new ComponentName(this, BootJobService.class))
                .setMinimumLatency(INTERVAL)
                .setOverrideDeadline(INTERVAL + 60 * 1000) // 最多延迟一分钟
                .setRequiresCharging(false)
                .setPersisted(true)
                .build();
        jobScheduler.schedule(jobInfo);
    }

    private void getBootRate(Context context) {
        SharedPreferences sp = context.getSharedPreferences("boot_data", Context.MODE_PRIVATE);
        String key = new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault()).format(new Date());
        int bootCount = sp.getInt(key + "_boot_count", 0);
        int shutdownCount = sp.getInt(key + "_shutdown_count", 0);
        double rate = bootCount * 1.0 / (bootCount + shutdownCount);
        Log.i(TAG, "Boot rate: " + rate);
        // TODO: 将数据保存到日志文件中
    }
}

可以在应用启动时启动定时任务：

public class MainActivity extends AppCompatActivity {
    private static final String TAG = "MainActivity";

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

    private void scheduleJob() {
        JobScheduler jobScheduler = (JobScheduler) getSystemService(Context.JOB_SCHEDULER_SERVICE);
        if (jobScheduler == null) {
            return;
        }
        JobInfo jobInfo = new JobInfo.Builder(BootJobService.JOB_ID, new ComponentName(this, BootJobService.class))
                .setMinimumLatency(BootJobService.INTERVAL)
                .setOverrideDeadline(BootJobService.INTERVAL + 60 * 1000) // 最多延迟一分钟
                .setRequiresCharging(false)
                .setPersisted(true)
                .build();
        jobScheduler.schedule(jobInfo);
        Log.i(TAG, "Job scheduled");
    }
}

最后，可以使用File类将数据保存到日志文件中。