Re: Copying collection without duplicates

From:

Karsten Wutzke <kwutzke@web.de>

Newsgroups:

comp.lang.java.programmer

Date:

Sat, 11 Aug 2007 11:21:51 -0700

Message-ID:

<1186856511.319593.186780@d55g2000hsg.googlegroups.com>

On 11 Aug., 00:29, Danno <dh.evolutionn...@gmail.com> wrote:

On Aug 10, 8:30 am, Karsten Wutzke <kwut...@web.de> wrote:

Hello!

I have the following method overriding Collection.addAll:

@Override
public boolean addAll(int index, Collection<? extends E> cln)
{
        if ( containsAll(cln) )
        {
                return false;
        }

        //build list without dupes (always)
        ArrayList<E> al = new ArrayList<E>(cln.size());

        Iterator<? extends E> itr = cln.iterator();

        while ( itr.hasNext() )
        {
                E elem = itr.next();

                if ( !contains(elem) )
                {
                        al.add(elem);
                }
        }

        cln = al;

        //allows dupes and nulls
        return super.addAll(index, cln);

}

Is there any faster way without overriding other methods?

Karsten

Yep!

Set<?> uniqueCollection = new TreeSet(collection);

Hmm how does this skip duplicates?

Karsten