how to sort date in descending order using comparator
date, datetime, dictionary, java, sorting
Solution
But i couldn't able to sort the date in descending order.
Two easy options:
- You could just reverse your comparison yourself, using `secondDate.compareTo(firstDate)`. (I assume that in your real code you're actually returning `retVal`; it's ignored in your posted code.)
- Call `Collections.reverseOrder(Comparator)` to create a comparator with the reverse order of the original one.
Problem
I have a bean object `testBean` with getter setter and methods.I am retrieving the results from the database and storing it in a `TreeMap` The Output of the `Map` will look like this: ``` {Student1 = [testBean[Dept=Science,ID=12,grade=A,Date=12-Jan-2013]] [testBean[Dept=Science,ID=12,grade=B,Date=14-Mar-2013]] {Student2 = [testBean[Dept=Science,ID=02,grade=A,Date=12-Jan-2013]] [testBean[Dept=Science,ID=02,grade=A,Date=14-Mar-2013]] ``` I need the Output to be arranged in Descending order so that the latest date comes first. So I am using a comparator to sort the date: ``` public int DateCompare(Object studentObj, Object anotherStudentObj) { SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy"); String value = ((testBean) studentObj).getDateTmTrans(); String value1 = ((testBean) anotherStudentObj).getDateTmTrans(); int retVal = 0; try { Date firstDate = dateFormat.parse(value); Date secondDate = dateFormat.parse(value1); retVal = firstDate.compareTo(secondDate); } catch (ParseException e) { e.printStackTrace(); } return 0; } ``` But I couldn't able to sort the date in descending order. Is there any solution to get the desired output? Any suggestions are welcome Thanks in advance