android - Storing ArrayList in onSavedInstanceState -

i'm running asynctask in fragment class , populating listview result. run asynctask first time fragment instantiated.

how store the arraylist of objects created in asynctask in onsavedinstance can retrieve them later?

i tried using putparcelablearraylist still nullpointerexception when try retrieve it.

thanks help

stops:

    public class stops implements parcelable{  private string station_name; private arraylist<stops> stoptitles;  public stops() {  }  public stops(parcel source) {     station_name = source.readstring();     source.readtypedlist(stoptitles, stops.creator); }  public string getstation_name() {     return station_name; }  public void setstation_name(string station_name) {     this.station_name = station_name; }  public void setstoptitles(arraylist<stops> stoptitles) {     this.stoptitles = stoptitles; }  public arraylist<stops> getstoptitles() {     return stoptitles; }  @override public string tostring() {     return station_name; }  @override public int describecontents() {     // todo auto-generated method stub     return 0; }  @override public void writetoparcel(parcel dest, int arg1) {     // todo auto-generated method stub     dest.writestring(station_name);     dest.writelist(stoptitles); }   public static final parcelable.creator<stops> creator = new parcelable.creator<stops>() {          @override         public stops createfromparcel(parcel in) {             return new stops(in);         }          @override         public stops[] newarray(int size) {             return new stops[size];         }  }; 

}

have made parcelable implementation of object holding in arraylist? if object not parcelable cannot pass list onsavedinstance example code:

        public class parcelableobject implements parcelable {         string field;             @override             public int describecontents() {                 return 0;             }              @override             public void writetoparcel(parcel dest, int flags) {                 dest.writevalue(field);                      }              public static final parcelable.creator<parcelableobject> creator =                  new parcelable.creator<parcelableobject>() {                  public parcelableobject createfromparcel(parcel in) {                     parcelableobject obj = new parcelableobject();                     obj.readfromparcel(in)                     return obj;                 }                  public parcelableobject[] newarray(int size) {                      return new parcelableobject[size];                 }            };          private void readfromparcel(parcel in) {                field = in.readstring()         } }