List java do not work on loop

Question

I have a list of items and in a for loop i'm trying to compare this list but the list make ArrayOutOfBoundsException.

Out of the for loop the list has 4 items (0,1,2,3) but in the for have only 3 (0,1,2) when I try to access the last item an exception is raised.

List<Relatorio> relatorios = new RelatorioDao().listaTudoEmpresa(userWeb.logado);
        for(int i = 0; i < relatorios.size(); i++){
            if(!contem(relatorios.get(i))){
                relatorios.remove(i);
            }
        }

possible duplicate of [Remove objects from an ArrayList based on a given criteria](http://stackoverflow.com/questions/13316629/remove-objects-from-an-arraylist-based-on-a-given-criteria) — Denys Séguret, Apr 01 '13 at 17:06

score 2 · Answer 1 · answered Apr 01 '13 at 17:00

That's because when you remove the element, you make the list size smaller, thus shortening the loop.

Use the dedicated list iterator when you want to remove elements while iterating, it is safe for this operation :

    Iterator<Relatorio> it = relatorios.iterator();
    while (it.hasNext())
        if (...) {
            it.remove();
        }
    }

score 2 · Accepted Answer · answered Apr 01 '13 at 17:01

2

You should not remove items from non-iterator loop.

Consider doing this instead

for( Iterator<Realtorio> iter = realtorios.iterator( ); iter.hasNext( ); )
{
   Relatorio cur = iter.next( );

   if(!contem(cur)){
      iter.remove( );
   }
}

answered Apr 01 '13 at 17:01

Alexander Pogrebnyak

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score 0 · Answer 3 · edited May 23 '17 at 10:27

0

You cannot do a delete on an item in a list as you are iterating through it. You must use the remove that is on the iterator to do so.
See This post.

edited May 23 '17 at 10:27

Community

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1

answered Apr 01 '13 at 17:02

Romain Hippeau

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List java do not work on loop

3 Answers3