how to sort the array list by date in ascending order?

Question

I want sort the ToDo list by date in ascending order. Can you help me, Im a beginner in android field enter link description here

Welcome @santhosh karthik do some research before directly posting question here . this is surely a duplicate one . — ADM, Jan 04 '18 at 13:07
You can find the answer for both ascending and descending here https://stackoverflow.com/a/66772568/5915318 — David Kariuki, Mar 23 '21 at 23:21

score 7 · Answer 1 · answered Jan 04 '18 at 13:06

Try this for ascending and descending order of date

  Collections.sort(arrayList, byDate);

Method ascending and descending

     static final Comparator<HomeModel> byDate = new Comparator<HomeModel>() {
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy,MM,dd");

    public int compare(HomeModel ord1, HomeModel ord2) {
        Date d1 = null;
        Date d2 = null;
        try {
            d1 = sdf.parse(ord1.eventdate);
            d2 = sdf.parse(ord2.eventdate);
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


        //return (d1.getTime() > d2.getTime() ? -1 : 1);     //descending
       return (d1.getTime() > d2.getTime() ? 1 : -1);     //ascending
    }
    };

This is nice. Thank you – David Kariuki Mar 23 '21 at 22:36 — David Kariuki, Mar 23 '21 at 22:36

score 0 · Answer 2 · answered Jan 04 '18 at 13:04

private void sortOldToNew() {
        if (inspectionDataArrayList == null)
            inspectionDataArrayList = new ArrayList<>();

        Collections.sort(inspectionDataArrayList, new Comparator<ClsInspection>() {
            public int compare(ClsInspection o1, ClsInspection o2) {
                String strDt1 = o1.getInspectionDateTime(); // your first date here
                String strDt2 = o2.getInspectionDateTime(); // second date here

                if (Utility.isValueNull(strDt1) || Utility.isValueNull(strDt2))
                    return 0;
                else {
                    Date dt1 = Utility.convertStringDateToDate(GMT_DATE_FORMAT, strDt1);
                    Date dt2 = Utility.convertStringDateToDate(GMT_DATE_FORMAT, strDt2);
                    if (dt1 == null || dt2 == null)
                        return 0;
                    return dt1.compareTo(dt2);
                }
            }
        });
        setAdapter(inspectionDataArrayList);
    }

where , String GMT_DATE_FORMAT = "yyyy-MM-dd HH:mm:ss";

how to sort the array list by date in ascending order?

2 Answers2