Make this service run in the foreground, supplying the ongoing notification to be shown to the user while in this state. By default services are background, meaning that if the system needs to kill them to reclaim more memory (such as to display a large page in a web browser), they can be killed without too much harm. You can set this flag if killing your service would be disruptive to the user, such as if your service is performing background music playback, so the user would notice if their music stopped playing.

If you need your application to run on platform versions prior to API level 5, you can use the following model to call the the older setForeground() or this modern method as appropriate:

private static final Class
       [] mSetForegroundSignature = new Class[] {
          boolean.class};private static final Class
       [] mStartForegroundSignature = new Class[] {
          int.class, Notification.class};private static final Class
       [] mStopForegroundSignature = new Class[] {
          boolean.class};private NotificationManager mNM;private Method mSetForeground;private Method mStartForeground;private Method mStopForeground;private Object[] mSetForegroundArgs = new Object[1];private Object[] mStartForegroundArgs = new Object[2];private Object[] mStopForegroundArgs = new Object[1];void invokeMethod(Method method, Object[] args) {
          try {
              method.invoke(this, args);    } catch (InvocationTargetException e) {
              // Should not happen.        Log.w("ApiDemos", "Unable to invoke method", e);    } catch (IllegalAccessException e) {
              // Should not happen.        Log.w("ApiDemos", "Unable to invoke method", e);    }}/** * This is a wrapper around the new startForeground method, using the older * APIs if it is not available. */void startForegroundCompat(int id, Notification notification) {
          // If we have the new startForeground API, then use it.    if (mStartForeground != null) {
              mStartForegroundArgs[0] = Integer.valueOf(id);        mStartForegroundArgs[1] = notification;        invokeMethod(mStartForeground, mStartForegroundArgs);        return;    }    // Fall back on the old API.    mSetForegroundArgs[0] = Boolean.TRUE;    invokeMethod(mSetForeground, mSetForegroundArgs);    mNM.notify(id, notification);}/** * This is a wrapper around the new stopForeground method, using the older * APIs if it is not available. */void stopForegroundCompat(int id) {
          // If we have the new stopForeground API, then use it.    if (mStopForeground != null) {
              mStopForegroundArgs[0] = Boolean.TRUE;        invokeMethod(mStopForeground, mStopForegroundArgs);        return;    }    // Fall back on the old API.  Note to cancel BEFORE changing the    // foreground state, since we could be killed at that point.    mNM.cancel(id);    mSetForegroundArgs[0] = Boolean.FALSE;    invokeMethod(mSetForeground, mSetForegroundArgs);}@Overridepublic void onCreate() {
          mNM = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);    try {
              mStartForeground = getClass().getMethod("startForeground",                mStartForegroundSignature);        mStopForeground = getClass().getMethod("stopForeground",                mStopForegroundSignature);        return;    } catch (NoSuchMethodException e) {
              // Running on an older platform.        mStartForeground = mStopForeground = null;    }    try {
              mSetForeground = getClass().getMethod("setForeground",                mSetForegroundSignature);    } catch (NoSuchMethodException e) {
              throw new IllegalStateException(                "OS doesn't have Service.startForeground OR Service.setForeground!");    }}@Overridepublic void onDestroy() {
          // Make sure our notification is gone.    stopForegroundCompat(R.string.foreground_service_started);}