Java sorting List

Question

I got a List in java. I get values from a SQL query.

public void ReloadPages() throws Exception {        
    try (Connection conn = Framework.GetDatabaseManager().GetBone().getConnection()) {
        try (ResultSet set = conn.createStatement().executeQuery("SELECT * FROM habbo_shop_pages")) {
            while (set.next()) {
                int Id = set.getInt(1);

                Pages.put(Id, new CatalogPage(set));
            }
        }
    }

    System.out.println("Loaded " + Pages.size() + " Catalog Page(s).");
}

Then I store it all. In another function, I want to retrieve certain pages from a parentid.

public LinkedList<CatalogPage> getSubPages(int parentId) {
    LinkedList<CatalogPage> pages = new LinkedList<>();

    for (CatalogPage page : this.Pages.values()) {
        if (page.getParentId() != parentId) {
            continue;
        }

        pages.add(page);
    }

    return pages;
}

How do I order the list? Now id 4 is above in the shop and 1 at the bottom, but I want it ordered by id. ORDER BY in query doesn't work.

Answer 1

Have your class implement Comparable and provide said sort ordering in compareTo method. And to sort, simply use Collections#sort, although be aware that it's an inline sort.

Answer 2

You want to sort the list in reverse order then try this:

Collections.sort(list,Collections.reverseOrder());