The Alarm Manager holds a CPU wake lock as long as the alarm receiver's * onReceive() method is executing. This guarantees that the phone will not sleep * until you have finished handling the broadcast. Once onReceive() returns, the * Alarm Manager releases this wake lock. This means that the phone will in some * cases sleep as soon as your onReceive() method completes. If your alarm receiver * called {@link android.content.Context#startService Context.startService()}, it * is possible that the phone will sleep before the requested service is launched. * To prevent this, your BroadcastReceiver and Service will need to implement a * separate wake lock policy to ensure that the phone continues running until the * service becomes available. * *
Note: The Alarm Manager is intended for cases where you want to have * your application code run at a specific time, even if your application is * not currently running. For normal timing operations (ticks, timeouts, * etc) it is easier and much more efficient to use * {@link android.os.Handler}. * *
Note: Beginning with API 19 * ({@link android.os.Build.VERSION_CODES#KITKAT}) alarm delivery is inexact: * the OS will shift alarms in order to minimize wakeups and battery use. There are * new APIs to support applications which need strict delivery guarantees; see * {@link #setWindow(int, long, long, PendingIntent)} and * {@link #setExact(int, long, PendingIntent)}. Applications whose {@code targetSdkVersion} * is earlier than API 19 will continue to see the previous behavior in which all * alarms are delivered exactly when requested. * *
You do not * instantiate this class directly; instead, retrieve it through * {@link android.content.Context#getSystemService * Context.getSystemService(Context.ALARM_SERVICE)}. */ public class AlarmManager { private static final String TAG = "AlarmManager"; /** * Alarm time in {@link System#currentTimeMillis System.currentTimeMillis()} * (wall clock time in UTC), which will wake up the device when * it goes off. */ public static final int RTC_WAKEUP = 0; /** * Alarm time in {@link System#currentTimeMillis System.currentTimeMillis()} * (wall clock time in UTC). This alarm does not wake the * device up; if it goes off while the device is asleep, it will not be * delivered until the next time the device wakes up. */ public static final int RTC = 1; /** * Alarm time in {@link android.os.SystemClock#elapsedRealtime * SystemClock.elapsedRealtime()} (time since boot, including sleep), * which will wake up the device when it goes off. */ public static final int ELAPSED_REALTIME_WAKEUP = 2; /** * Alarm time in {@link android.os.SystemClock#elapsedRealtime * SystemClock.elapsedRealtime()} (time since boot, including sleep). * This alarm does not wake the device up; if it goes off while the device * is asleep, it will not be delivered until the next time the device * wakes up. */ public static final int ELAPSED_REALTIME = 3; /** * Broadcast Action: Sent after the value returned by * {@link #getNextAlarmClock()} has changed. * *
This is a protected intent that can only be sent by the system. * It is only sent to registered receivers.
*/ @SdkConstant(SdkConstant.SdkConstantType.BROADCAST_INTENT_ACTION) public static final String ACTION_NEXT_ALARM_CLOCK_CHANGED = "android.app.action.NEXT_ALARM_CLOCK_CHANGED"; /** @hide */ public static final long WINDOW_EXACT = 0; /** @hide */ public static final long WINDOW_HEURISTIC = -1; private final IAlarmManager mService; private final boolean mAlwaysExact; /** * package private on purpose */ AlarmManager(IAlarmManager service, Context ctx) { mService = service; final int sdkVersion = ctx.getApplicationInfo().targetSdkVersion; mAlwaysExact = (sdkVersion < Build.VERSION_CODES.KITKAT); } private long legacyExactLength() { return (mAlwaysExact ? WINDOW_EXACT : WINDOW_HEURISTIC); } /** *Schedule an alarm. Note: for timing operations (ticks, timeouts, * etc) it is easier and much more efficient to use {@link android.os.Handler}. * If there is already an alarm scheduled for the same IntentSender, that previous * alarm will first be canceled. * *
If the stated trigger time is in the past, the alarm will be triggered * immediately. If there is already an alarm for this Intent * scheduled (with the equality of two intents being defined by * {@link Intent#filterEquals}), then it will be removed and replaced by * this one. * *
* The alarm is an Intent broadcast that goes to a broadcast receiver that * you registered with {@link android.content.Context#registerReceiver} * or through the <receiver> tag in an AndroidManifest.xml file. * *
* Alarm intents are delivered with a data extra of type int called * {@link Intent#EXTRA_ALARM_COUNT Intent.EXTRA_ALARM_COUNT} that indicates * how many past alarm events have been accumulated into this intent * broadcast. Recurring alarms that have gone undelivered because the * phone was asleep may have a count greater than one when delivered. * *
* Note: Beginning in API 19, the trigger time passed to this method * is treated as inexact: the alarm will not be delivered before this time, but * may be deferred and delivered some time later. The OS will use * this policy in order to "batch" alarms together across the entire system, * minimizing the number of times the device needs to "wake up" and minimizing * battery use. In general, alarms scheduled in the near future will not * be deferred as long as alarms scheduled far in the future. * *
* With the new batching policy, delivery ordering guarantees are not as * strong as they were previously. If the application sets multiple alarms, * it is possible that these alarms' actual delivery ordering may not match * the order of their requested delivery times. If your application has * strong ordering requirements there are other APIs that you can use to get * the necessary behavior; see {@link #setWindow(int, long, long, PendingIntent)} * and {@link #setExact(int, long, PendingIntent)}. * *
* Applications whose {@code targetSdkVersion} is before API 19 will * continue to get the previous alarm behavior: all of their scheduled alarms * will be treated as exact. *
Like {@link #set}, except you can also supply a period at which * the alarm will automatically repeat. This alarm continues * repeating until explicitly removed with {@link #cancel}. If the stated * trigger time is in the past, the alarm will be triggered immediately, with an * alarm count depending on how far in the past the trigger time is relative * to the repeat interval. * *
If an alarm is delayed (by system sleep, for example, for non * _WAKEUP alarm types), a skipped repeat will be delivered as soon as * possible. After that, future alarms will be delivered according to the * original schedule; they do not drift over time. For example, if you have * set a recurring alarm for the top of every hour but the phone was asleep * from 7:45 until 8:45, an alarm will be sent as soon as the phone awakens, * then the next alarm will be sent at 9:00. * *
If your application wants to allow the delivery times to drift in * order to guarantee that at least a certain time interval always elapses * between alarms, then the approach to take is to use one-time alarms, * scheduling the next one yourself when handling each alarm delivery. * *
* Note: as of API 19, all repeating alarms are inexact. If your * application needs precise delivery times then it must use one-time * exact alarms, rescheduling each time as described above. Legacy applications * whose {@code targetSdkVersion} is earlier than API 19 will continue to have all * of their alarms, including repeating alarms, treated as exact. * * @param type One of {@link #ELAPSED_REALTIME}, {@link #ELAPSED_REALTIME_WAKEUP}, * {@link #RTC}, or {@link #RTC_WAKEUP}. * @param triggerAtMillis time in milliseconds that the alarm should first * go off, using the appropriate clock (depending on the alarm type). * @param intervalMillis interval in milliseconds between subsequent repeats * of the alarm. * @param operation Action to perform when the alarm goes off; * typically comes from {@link PendingIntent#getBroadcast * IntentSender.getBroadcast()}. * * @see android.os.Handler * @see #set * @see #setExact * @see #setWindow * @see #cancel * @see android.content.Context#sendBroadcast * @see android.content.Context#registerReceiver * @see android.content.Intent#filterEquals * @see #ELAPSED_REALTIME * @see #ELAPSED_REALTIME_WAKEUP * @see #RTC * @see #RTC_WAKEUP */ public void setRepeating(int type, long triggerAtMillis, long intervalMillis, PendingIntent operation) { setImpl(type, triggerAtMillis, legacyExactLength(), intervalMillis, operation, null, null); } /** * Schedule an alarm to be delivered within a given window of time. This method * is similar to {@link #set(int, long, PendingIntent)}, but allows the * application to precisely control the degree to which its delivery might be * adjusted by the OS. This method allows an application to take advantage of the * battery optimizations that arise from delivery batching even when it has * modest timeliness requirements for its alarms. * *
* This method can also be used to achieve strict ordering guarantees among * multiple alarms by ensuring that the windows requested for each alarm do * not intersect. * *
* When precise delivery is not required, applications should use the standard * {@link #set(int, long, PendingIntent)} method. This will give the OS the most * flexibility to minimize wakeups and battery use. For alarms that must be delivered * at precisely-specified times with no acceptable variation, applications can use * {@link #setExact(int, long, PendingIntent)}. * * @param type One of {@link #ELAPSED_REALTIME}, {@link #ELAPSED_REALTIME_WAKEUP}, * {@link #RTC}, or {@link #RTC_WAKEUP}. * @param windowStartMillis The earliest time, in milliseconds, that the alarm should * be delivered, expressed in the appropriate clock's units (depending on the alarm * type). * @param windowLengthMillis The length of the requested delivery window, * in milliseconds. The alarm will be delivered no later than this many * milliseconds after {@code windowStartMillis}. Note that this parameter * is a duration, not the timestamp of the end of the window. * @param operation Action to perform when the alarm goes off; * typically comes from {@link PendingIntent#getBroadcast * IntentSender.getBroadcast()}. * * @see #set * @see #setExact * @see #setRepeating * @see #cancel * @see android.content.Context#sendBroadcast * @see android.content.Context#registerReceiver * @see android.content.Intent#filterEquals * @see #ELAPSED_REALTIME * @see #ELAPSED_REALTIME_WAKEUP * @see #RTC * @see #RTC_WAKEUP */ public void setWindow(int type, long windowStartMillis, long windowLengthMillis, PendingIntent operation) { setImpl(type, windowStartMillis, windowLengthMillis, 0, operation, null, null); } /** * Schedule an alarm to be delivered precisely at the stated time. * *
* This method is like {@link #set(int, long, PendingIntent)}, but does not permit * the OS to adjust the delivery time. The alarm will be delivered as nearly as * possible to the requested trigger time. * *
* Note: only alarms for which there is a strong demand for exact-time * delivery (such as an alarm clock ringing at the requested time) should be * scheduled as exact. Applications are strongly discouraged from using exact * alarms unnecessarily as they reduce the OS's ability to minimize battery use. * * @param type One of {@link #ELAPSED_REALTIME}, {@link #ELAPSED_REALTIME_WAKEUP}, * {@link #RTC}, or {@link #RTC_WAKEUP}. * @param triggerAtMillis time in milliseconds that the alarm should go * off, using the appropriate clock (depending on the alarm type). * @param operation Action to perform when the alarm goes off; * typically comes from {@link PendingIntent#getBroadcast * IntentSender.getBroadcast()}. * * @see #set * @see #setRepeating * @see #setWindow * @see #cancel * @see android.content.Context#sendBroadcast * @see android.content.Context#registerReceiver * @see android.content.Intent#filterEquals * @see #ELAPSED_REALTIME * @see #ELAPSED_REALTIME_WAKEUP * @see #RTC * @see #RTC_WAKEUP */ public void setExact(int type, long triggerAtMillis, PendingIntent operation) { setImpl(type, triggerAtMillis, WINDOW_EXACT, 0, operation, null, null); } /** * Schedule an alarm that represents an alarm clock. * * The system may choose to display information about this alarm to the user. * *
* This method is like {@link #setExact(int, long, PendingIntent)}, but implies * {@link #RTC_WAKEUP}. * * @param info * @param operation Action to perform when the alarm goes off; * typically comes from {@link PendingIntent#getBroadcast * IntentSender.getBroadcast()}. * * @see #set * @see #setRepeating * @see #setWindow * @see #setExact * @see #cancel * @see #getNextAlarmClock() * @see android.content.Context#sendBroadcast * @see android.content.Context#registerReceiver * @see android.content.Intent#filterEquals */ public void setAlarmClock(AlarmClockInfo info, PendingIntent operation) { setImpl(RTC_WAKEUP, info.getTriggerTime(), WINDOW_EXACT, 0, operation, null, info); } /** @hide */ @SystemApi public void set(int type, long triggerAtMillis, long windowMillis, long intervalMillis, PendingIntent operation, WorkSource workSource) { setImpl(type, triggerAtMillis, windowMillis, intervalMillis, operation, workSource, null); } private void setImpl(int type, long triggerAtMillis, long windowMillis, long intervalMillis, PendingIntent operation, WorkSource workSource, AlarmClockInfo alarmClock) { if (triggerAtMillis < 0) { /* NOTYET if (mAlwaysExact) { // Fatal error for KLP+ apps to use negative trigger times throw new IllegalArgumentException("Invalid alarm trigger time " + triggerAtMillis); } */ triggerAtMillis = 0; } try { mService.set(type, triggerAtMillis, windowMillis, intervalMillis, operation, workSource, alarmClock); } catch (RemoteException ex) { } } /** * Available inexact recurrence interval recognized by * {@link #setInexactRepeating(int, long, long, PendingIntent)} * when running on Android prior to API 19. */ public static final long INTERVAL_FIFTEEN_MINUTES = 15 * 60 * 1000; /** * Available inexact recurrence interval recognized by * {@link #setInexactRepeating(int, long, long, PendingIntent)} * when running on Android prior to API 19. */ public static final long INTERVAL_HALF_HOUR = 2*INTERVAL_FIFTEEN_MINUTES; /** * Available inexact recurrence interval recognized by * {@link #setInexactRepeating(int, long, long, PendingIntent)} * when running on Android prior to API 19. */ public static final long INTERVAL_HOUR = 2*INTERVAL_HALF_HOUR; /** * Available inexact recurrence interval recognized by * {@link #setInexactRepeating(int, long, long, PendingIntent)} * when running on Android prior to API 19. */ public static final long INTERVAL_HALF_DAY = 12*INTERVAL_HOUR; /** * Available inexact recurrence interval recognized by * {@link #setInexactRepeating(int, long, long, PendingIntent)} * when running on Android prior to API 19. */ public static final long INTERVAL_DAY = 2*INTERVAL_HALF_DAY; /** * Schedule a repeating alarm that has inexact trigger time requirements; * for example, an alarm that repeats every hour, but not necessarily at * the top of every hour. These alarms are more power-efficient than * the strict recurrences traditionally supplied by {@link #setRepeating}, since the * system can adjust alarms' delivery times to cause them to fire simultaneously, * avoiding waking the device from sleep more than necessary. * *
Your alarm's first trigger will not be before the requested time, * but it might not occur for almost a full interval after that time. In * addition, while the overall period of the repeating alarm will be as * requested, the time between any two successive firings of the alarm * may vary. If your application demands very low jitter, use * one-shot alarms with an appropriate window instead; see {@link * #setWindow(int, long, long, PendingIntent)} and * {@link #setExact(int, long, PendingIntent)}. * *
* As of API 19, all repeating alarms are inexact. Because this method has * been available since API 3, your application can safely call it and be * assured that it will get similar behavior on both current and older versions * of Android. * * @param type One of {@link #ELAPSED_REALTIME}, {@link #ELAPSED_REALTIME_WAKEUP}, * {@link #RTC}, or {@link #RTC_WAKEUP}. * @param triggerAtMillis time in milliseconds that the alarm should first * go off, using the appropriate clock (depending on the alarm type). This * is inexact: the alarm will not fire before this time, but there may be a * delay of almost an entire alarm interval before the first invocation of * the alarm. * @param intervalMillis interval in milliseconds between subsequent repeats * of the alarm. Prior to API 19, if this is one of INTERVAL_FIFTEEN_MINUTES, * INTERVAL_HALF_HOUR, INTERVAL_HOUR, INTERVAL_HALF_DAY, or INTERVAL_DAY * then the alarm will be phase-aligned with other alarms to reduce the * number of wakeups. Otherwise, the alarm will be set as though the * application had called {@link #setRepeating}. As of API 19, all repeating * alarms will be inexact and subject to batching with other alarms regardless * of their stated repeat interval. * @param operation Action to perform when the alarm goes off; * typically comes from {@link PendingIntent#getBroadcast * IntentSender.getBroadcast()}. * * @see android.os.Handler * @see #set * @see #cancel * @see android.content.Context#sendBroadcast * @see android.content.Context#registerReceiver * @see android.content.Intent#filterEquals * @see #ELAPSED_REALTIME * @see #ELAPSED_REALTIME_WAKEUP * @see #RTC * @see #RTC_WAKEUP * @see #INTERVAL_FIFTEEN_MINUTES * @see #INTERVAL_HALF_HOUR * @see #INTERVAL_HOUR * @see #INTERVAL_HALF_DAY * @see #INTERVAL_DAY */ public void setInexactRepeating(int type, long triggerAtMillis, long intervalMillis, PendingIntent operation) { setImpl(type, triggerAtMillis, WINDOW_HEURISTIC, intervalMillis, operation, null, null); } /** * Remove any alarms with a matching {@link Intent}. * Any alarm, of any type, whose Intent matches this one (as defined by * {@link Intent#filterEquals}), will be canceled. * * @param operation IntentSender which matches a previously added * IntentSender. * * @see #set */ public void cancel(PendingIntent operation) { try { mService.remove(operation); } catch (RemoteException ex) { } } /** * Set the system wall clock time. * Requires the permission android.permission.SET_TIME. * * @param millis time in milliseconds since the Epoch */ public void setTime(long millis) { try { mService.setTime(millis); } catch (RemoteException ex) { } } /** * Set the system default time zone. * Requires the permission android.permission.SET_TIME_ZONE. * * @param timeZone in the format understood by {@link java.util.TimeZone} */ public void setTimeZone(String timeZone) { try { mService.setTimeZone(timeZone); } catch (RemoteException ex) { } } /** * Gets information about the next alarm clock currently scheduled. * * The alarm clocks considered are those scheduled by {@link #setAlarmClock} * from any package of the calling user. * * @see #setAlarmClock * @see AlarmClockInfo */ public AlarmClockInfo getNextAlarmClock() { return getNextAlarmClock(UserHandle.myUserId()); } /** * Gets information about the next alarm clock currently scheduled. * * The alarm clocks considered are those scheduled by {@link #setAlarmClock} * from any package of the given {@parm userId}. * * @see #setAlarmClock * @see AlarmClockInfo * * @hide */ public AlarmClockInfo getNextAlarmClock(int userId) { try { return mService.getNextAlarmClock(userId); } catch (RemoteException ex) { return null; } } /** * An immutable description of an alarm clock. * * @see AlarmManager#setAlarmClock * @see AlarmManager#getNextAlarmClock */ public static final class AlarmClockInfo implements Parcelable { private final long mTriggerTime; private final PendingIntent mShowIntent; /** * Creates a new alarm clock description. * * @param triggerTime time at which the underlying alarm is triggered in wall time * milliseconds since the epoch * @param showIntent an intent that can be used to show or edit details of * the alarm clock. */ public AlarmClockInfo(long triggerTime, PendingIntent showIntent) { mTriggerTime = triggerTime; mShowIntent = showIntent; } /** * Use the {@link #CREATOR} * @hide */ AlarmClockInfo(Parcel in) { mTriggerTime = in.readLong(); mShowIntent = in.readParcelable(PendingIntent.class.getClassLoader()); } /** * Returns the time at which the alarm is going to trigger. * * This value is UTC wall clock time in milliseconds, as returned by * {@link System#currentTimeMillis()} for example. */ public long getTriggerTime() { return mTriggerTime; } /** * Returns an intent intent that can be used to show or edit details of the alarm clock in * the application that scheduled it. * *
Beware that any application can retrieve and send this intent,
* potentially with additional fields filled in. See
* {@link PendingIntent#send(android.content.Context, int, android.content.Intent)
* PendingIntent.send()} and {@link android.content.Intent#fillIn Intent.fillIn()}
* for details.
*/
public PendingIntent getShowIntent() {
return mShowIntent;
}
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeLong(mTriggerTime);
dest.writeParcelable(mShowIntent, flags);
}
public static final Creator