Sorting a list of ArrayList by date in the ArrayList

Question

I have a list of ArrayList, and each arraylist consists of a date and a string. I want to sort the list according to the date in the arraylist. I tried looking for answers but cant find it online. Most of the examples are sorting a list of objects by date. Any suggestions?

public List<ArrayList> SuggestionReport() {
    Query q = em.createQuery("SELECT s FROM SuggestionEntity s");
    List<ArrayList> report = new ArrayList();
    for (Object o : q.getResultList()) {
        suggestionEntity = (SuggestionEntity) o;
        ArrayList suggestion = new ArrayList();
        suggestion.add(suggestionEntity.getSuggestionDate());
        suggestion.add(suggestionEntity.getContent());
        report.add(suggestion);
    }

    return report;
}

ps. I want to sort the list before returning the list

you can query by date.try this sql "SELECT s FROM SuggestionEntity s order by s.suggestionDate desc".the "s.suggestionDate" is your database field .than the result was sort already. — Blade Master, Oct 12 '13 at 08:38
http://stackoverflow.com/questions/2784514/sort-arraylist-of-custom-objects-by-property — Salem, Oct 12 '13 at 08:41

Suresh Atta · Accepted Answer · 2013-10-12T08:46:39.150

4

Need not to write extra code, Just change your query to

SELECT s FROM SuggestionEntity s order by  suggestion_date ASC|DESC

Where suggestion_date is your column name.

ASC|DESC is order you want, choose ASC or DESC based on your requirment.

Learn more here about order by

edited Oct 12 '13 at 08:46

answered Oct 12 '13 at 08:38

Suresh Atta

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Thanks alot!! But this is applicable to java ejb query as well right? – ayampenyet Oct 12 '13 at 08:57
Ofcourse, It supports `sql` right ? Syntax might change. But concept is same. :) – Suresh Atta Oct 12 '13 at 08:59
Thanks a lot for the help! Appreciate it :) – ayampenyet Oct 12 '13 at 09:21

score 0 · Answer 2 · answered Oct 12 '13 at 08:38

0

You should write your own comparator, and then sort it like following:

Collections.sort(list, myComparator);

answered Oct 12 '13 at 08:38

Vova Pronyshyn

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Sorting a list of ArrayList by date in the ArrayList

2 Answers2