Android - 后台服务不运行，如果手机睡着

Question

我想为我的学校提出申请，其中包括一个后台服务，将下载学生的成绩和作业历史记录。该服务每小时由AlarmManager调用，并且只有在设备开机时才有效。一旦设备打开（从休眠状态开始;设备未完全关闭），AlarmManager触发该服务。这是广播接收器，其中包括AlarmManager的代码：

import android.app.AlarmManager; 
import android.app.PendingIntent; 
import android.content.Context; 
import android.content.Intent; 
import android.util.Log; 
import android.support.v4.content.WakefulBroadcastReceiver; 

public class ServiceAlarmReceiver extends WakefulBroadcastReceiver {  

private final String TAG = "com.example.ahsandroidapplication"; 

@Override 
public void onReceive(Context context, Intent intent) { 

    Log.i(TAG, "Broadcast received"); 
    Intent gradeNotificationServiceIntent = new Intent(context, GradeNotificationService.class); 
    //context.startService(gradeNotificationServiceIntent); 
    startWakefulService(context, gradeNotificationServiceIntent); 
} 

public static void setAlarm(Context context){ 

    System.out.println("Service started"); 

    long alertTime = System.currentTimeMillis() + 1000 * 60 * 60; 
    Intent alertIntent = new Intent(context, ServiceAlarmReceiver.class); 

    alertIntent.setAction("com.example.ahsandroidapplication.servicealarmbroadcast"); 

    AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE); 
    //alarmManager.set(AlarmManager.RTC_WAKEUP, alertTime, PendingIntent.getBroadcast(context, 1, alertIntent, 
    //  PendingIntent.FLAG_UPDATE_CURRENT)); 
    alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, alertTime, 1000 * 3600, PendingIntent.getBroadcast(context, 
      GradeNotificationService.SERVICE_ALARM_BROADCAST_ID, alertIntent, 
      PendingIntent.FLAG_UPDATE_CURRENT)); 


} 

public static void cancelAlarm(Context context) 
{ 
    Intent intent = new Intent(context, ServiceAlarmReceiver.class); 

    intent.setAction("com.example.ahsandroidapplication.servicealarmbroadcast"); 

    PendingIntent sender = PendingIntent.getBroadcast(context, 
      GradeNotificationService.SERVICE_ALARM_BROADCAST_ID, intent, 0); 
    AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE); 
    alarmManager.cancel(sender); 
} 
} 

因为广播接收，只有当手机处于开机状态，我相信问题出在接收器。

该服务还存在另一个问题。无论何时发布新成绩，都应该发送推送通知，但他们从未被发送。

下面是服务类的代码：

import org.jsoup.nodes.Document; 
import org.jsoup.nodes.Element; 

import android.app.IntentService; 
import android.app.Notification; 
import android.app.NotificationManager; 
import android.app.PendingIntent; 
import android.app.Service; 
import android.content.Context; 
import android.content.Intent; 
import android.net.ConnectivityManager; 
import android.net.NetworkInfo; 
import android.support.v4.app.NotificationCompat; 

public class GradeNotificationService extends IntentService { 

private Context context; 

public GradeNotificationService() { 
    super("GradeNotificationService"); 
    // TODO Auto-generated constructor stub 
} 

public static final int SERVICE_ALARM_BROADCAST_ID = 0; 

@Override 
protected void onHandleIntent(Intent intent) { 
    // TODO Auto-generated method stub 

    System.out.println("Grade notification services started"); 
    context = getApplicationContext(); 
    final Intent completeWakefulIntent = intent; 

    if(gradesChanged()){ 

     getAssignments(); 
    } 

    ServiceAlarmReceiver.completeWakefulIntent(completeWakefulIntent); 
} 


private boolean gradesChanged() { 

//Massive blocks of code that will take you forever to read 

} 

private void getAssignments(){ 


//Massive blocks of code that will take you forever to read 
//It is in this method that sendNotification() is used to send a notification 
//(at least that's what it's supposed to be doing) 


} 

private void sendNotification(String title, String message){ 

    NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context); 

    mBuilder.setSmallIcon(R.drawable.ic_launcher); 
    mBuilder.setContentTitle(title); 
    mBuilder.setContentText(message); 
    mBuilder.setDefaults(NotificationCompat.DEFAULT_SOUND); 
    mBuilder.setAutoCancel(true); 

    Intent resultIntent = new Intent(context, MainInterface.class); 

    PendingIntent resultPendingIntent = PendingIntent.getActivity(context, 0, resultIntent, 0); 
    mBuilder.setContentIntent(resultPendingIntent); 

    NotificationManager mNotificationManager = 
      (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE); 
    // mId allows you to update the notification later on. 
    mNotificationManager.notify(1, mBuilder.build()); 

} 

private boolean networkIsAvailable() { 

    ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); 
    NetworkInfo netInfo = cm.getActiveNetworkInfo(); 
    // return netInfo != null && netInfo.isConnectedOrConnecting(); 

    NetworkInfo mWifi = cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI); 

    return netInfo != null && netInfo.isConnectedOrConnecting() 
      || mWifi.isConnected(); 

} 

} 

谁能告诉我，我能做些什么，使这个服务运行的时候，手机是睡着了，或者为什么它不发送任何通知？任何帮助appriciated。

编辑：

这是大部分清单。目标SDK是21，最小为11：

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

<uses-sdk 
    android:minSdkVersion="11" 
    android:targetSdkVersion="21" /> 

<application 
    android:allowBackup="true" 
    android:label="@string/app_name" 
    android:icon="@drawable/ic_launcher"> 

    <service 
     android:name="com.example.ahsandroidapplication.GradeNotificationService" 
     android:enabled="true" > 
     <intent-filter> 
      <action android:name="com.example.ahsandroidapplication.ServiceAlarmReceiver" /> 
     </intent-filter> 
    </service> 

    <receiver android:name=".ServiceAlarmReceiver" 
     android:enabled="true"> 
     <intent-filter> 
     <action android:name="com.example.ahsandroidapplication.servicealarmbroadcast"></action> 
     </intent-filter> 
    </receiver> 

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

    <activity 
     android:name="MainInterface" 
     android:label="@string/app_name" > 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 

      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 

    <activity android:name="MainLogin" 
       android:label="@string/app_name"> 

    </activity> 

    <service android:enabled="true" 
     android:exported="false" 
     android:isolatedProcess="false" 
     android:label="@string/app_name" 
     android:name="AspenManager" > 
    </service> 

</application> 

Answer 1

“注：与API开始19（奇巧）报警交付是不精确的：操作系统将为了尽量减少唤醒和电池使用Shift报警有新API支持需要严格交付保证的应用程序;请参阅setWindow（int，long，long，PendingIntent）和setExact（int，long，PendingIntent）。targetSdkVersion早于API 19的应用程序将继续看到之前的行为，准确地在需要时提供。“

http://developer.android.com/reference/android/app/AlarmManager.html