public class RepeatTaskScheduler extends BroadcastReceiver {
    public static final String ACTION = "com.yourcompanyname.appname.action.RepeatTaskSchedule";
@Override
    public void onReceive(Context context, Intent intent) {
        if (ACTION.equals(action)) {
            checkEvent();
        }
    }
}
//在你想要的地方启动
public class YourActivity extends Activity{
    @Override
    public void onCreate() {
        super.onCreate();
        //如果interval的值太大会失效,几个小时没问题
        setRepeatTasks(1000, 1000 * 30);
    }
    private void setRepeatTasks(long triggerTime, long interval) {
            AlarmManager am = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
        Intent intent = new Intent(RepeatTaskScheduler.ACTION);
        //系统中如果有这个pendingIntent 取消
        PendingIntent pending = PendingIntent.getBroadcast(this, 0, intent,
                PendingIntent.FLAG_NO_CREATE);
        if (pending != null) {
            am.cancel(pending);
        }
        pending = PendingIntent.getBroadcast(this, 0, intent, 0);
        am.set(AlarmManager.RTC_WAKEUP, triggerTime, pending);
        am.setRepeating(AlarmManager.RTC_WAKEUP, triggerTime, interval, pending);
    }
}在AndroidManifest.xml中加入
<receiver android:name=".RepeatTaskScheduler">
    <intent-filter>
        <action android:name="com.yourcompanyname.appname.action.RepeatTaskSchedule" />
    </intent-filter>
</receiver>代码我没测试过,只介绍思路,有问题留言