我正在运行谷歌日历示例，然后我收到以下错误。 在eclipse中https://developers.google.com/google-apps/calendar/quickstart/java运行Java快速入门示例时，我收到错误代码：
Nov 23, 2015 12:23:29 PM com.google.api.client.util.store.FileDataStoreFactory setPermissionsToOwnerOnly
WARNING: unable to change permissions for everybody: C:\Users\Shree\.credentials\calendar-java-quickstart
Nov 23, 2015 12:23:29 PM com.google.api.client.util.store.FileDataStoreFactory setPermissionsToOwnerOnly
WARNING: unable to change permissions for owner: C:\Users\Shree\.credentials\calendar-java-quickstart
Exception in thread "main" java.lang.NullPointerException
at java.io.Reader.<init>(Unknown Source)
at java.io.InputStreamReader.<init>(Unknown Source)
at main.java.CalendarQuickstart.authorize(CalendarQuickstart.java:69)
at main.java.CalendarQuickstart.getCalendarService(CalendarQuickstart.java:92)
at main.java.CalendarQuickstart.main(CalendarQuickstart.java:104)
任何帮助