Formatting date correctly

Question

Hello stackoverflowers, Let's say i have a database with a row filled with dates, Okay?

Problem 1:

Like this one :

2013-06-01

So i want to translate this date to String

Input:

Tue Mar 01 00:00:00 EET 2013

As an example.. So how can i turn the output of the date like this:

Mar 2013 ?? Here's my codes:

date = new SimpleDateFormat("yyyy-MM-dd", Locale.ENGLISH)
                            .parse(mCursor.getString(mCursor
                                    .getColumnIndex(KEY_AVAILABILITYDATE)));
                    list.add(date);

Problem 2(Problem 1 must be solved first i guess):

Of course i want to sort the list i added the date to.

So i run this code:

Collections.sort(list);

But frankly it doesn't sort correctly! it's mixed - dates all wrongs.

Thanks for reading, i hope it's easy!

All Codes:

public ArrayList<Date> GetValues() {
ArrayList<Date> list = new ArrayList<Date>();
        Date date;
if (mCursor.moveToFirst()) {
            while (mCursor.isAfterLast() == false) {
                try {
                    date = new SimpleDateFormat("yyyy-MM-dd", Locale.ENGLISH)
                            .parse(mCursor.getString(mCursor
                                    .getColumnIndex(KEY_AVAILABILITYDATE)));
                    list.add(date);

                } catch (ParseException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                mCursor.moveToNext();
            }

        }

        Collections.sort(list);

        return list;

    }

After loosing some hope i decided to show you all codes:

Codes:

    Database DbHelper = new Database(
                    this.getSherlockActivity()).open();
            ArrayList<Date> headers = DbHelper.GetValues();

            HashSet<Date> hs = new HashSet<Date>();
            hs.addAll(headers);
            headers.clear();
            headers.addAll(hs);
                    Collections.sort(header,dateComparator);
            Collections.reverse(headers);

I'm using 3rd party library : StickyGridHeadersGridView so here's my adapter:

@Override
public int getCountForHeader(int header) {
    // TODO Auto-generated method stub
    return 1;
}

    @Override
    public int getNumHeaders() {
        // TODO Auto-generated method stub
        return headers.size();
    }

    @Override
public View getHeaderView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    if (convertView == null) {
        convertView = inflater.inflate(R.layout.header, parent, false);
        TextView tvheader = (TextView) convertView
                .findViewById(R.id.tvheader);
        String headertitle = headers.get(position).toString();
        if (headertitle.contains("01 00:00:00 EET")) {
            headertitle = headertitle.replace("01 00:00:00 EET", "");
        }
        if (headertitle.contains("01 00:00:00 EEST")) {
            headertitle = headertitle.replace("01 00:00:00 EEST", "");
        }
        if (headertitle.contains("02 00:00:00 EET")) {
            headertitle = headertitle.replace("02 00:00:00 EET", "");
        }
        if (headertitle.contains("02 00:00:00 EEST")) {
            headertitle = headertitle.replace("02 00:00:00 EEST", "");
        }
        if (headertitle.contains("15 00:00:00 EET")) {
            headertitle = headertitle.replace("15 00:00:00 EET", "");
        }
        // days
        if (headertitle.contains("Mon")) {
            headertitle = headertitle.replace("Mon", "");
        }
        if (headertitle.contains("Tue")) {
            headertitle = headertitle.replace("Tue", "");
        }
        if (headertitle.contains("Wed")) {
            headertitle = headertitle.replace("Wed", "");
        }
        if (headertitle.contains("Thu")) {
            headertitle = headertitle.replace("Thu", "");
        }
        if (headertitle.contains("Fri")) {
            headertitle = headertitle.replace("Fri", "");
        }
        if (headertitle.contains("Sat")) {
            headertitle = headertitle.replace("Sat", "");
        }
        if (headertitle.contains("Sun")) {
            headertitle = headertitle.replace("Sun", "");
        }

        // months
        if (headertitle.contains("Jan")) {
            headertitle = headertitle.replace("Jan", "January");
        }
        if (headertitle.contains("Feb")) {
            headertitle = headertitle.replace("Feb", "February");
        }
        if (headertitle.contains("Mar")) {
            headertitle = headertitle.replace("Mar", "March");
        }
        if (headertitle.contains("Apr")) {
            headertitle = headertitle.replace("Apr", "April");
        }
        if (headertitle.contains("Jun")) {
            headertitle = headertitle.replace("Jun", "June");
        }
        if (headertitle.contains("Jul")) {
            headertitle = headertitle.replace("Jul", "July");
        }
        if (headertitle.contains("Aug")) {
            headertitle = headertitle.replace("Aug", "August");
        }
        if (headertitle.contains("Sep")) {
            headertitle = headertitle.replace("Sep", "September");
        }
        if (headertitle.contains("Oct")) {
            headertitle = headertitle.replace("Oct", "October");
        }
        if (headertitle.contains("Nov")) {
            headertitle = headertitle.replace("Nov", "November");
        }
        if (headertitle.contains("Dec")) {
            headertitle = headertitle.replace("Dec", "December");
        }
        tvheader.setText(headertitle);

    }

However now the results are all mixed up and lost! the gridview is big and i only see :

September 2013 June 2013 July 2013

in each row. What can i do ? Thanks

Answer 1

So after 1 day of contuniously working on a fix, i have found out that the problem occured from GridViewStickyHeaders - external library.

The problem occurs once i scroll! the results all get messed.

Thanks for your contribution! your help really helped me! thanks =)

Answer 2

1) Use "MMM yyyy" as your regex, like so:

public class Main {
  public static void main(String args[]) {
    Date now = new Date();
    SimpleDateFormat format = new SimpleDateFormat("MMM yyyy", Locale.ENGLISH);
    System.out.println(format.format(now));
  }
}

> Sep 2013

2) Using a comparator with compareTo() shouldn't be necessary since Collections.sort(list) should sort a list of Dates chronologically by default.

Most likely, the problem lies somewhere in the code you're not showing but I can't be sure since you're not mocking the database so I can't run your code in Eclipse.

Source: http://docs.oracle.com/javase/tutorial/collections/interfaces/order.html

Answer 3

you need to build a comparator to compare two dates:

here is a code for it:

public static Comparator<Date> dateComparator = new Comparator<Date>()
{
    public int compare(Date date1, Date date2)
    {
        return date1.compareTo(date2);
    }
};

and you can call it using this line of code:

Collections.sort(list,dateComparator);

and this is how to use arrays instead of collections

Date[] arrayDates = new Date[list.size()];
arrayDates = list.toArray(arrayDates);
Arrays.sort(arrayDates, dateComparator);