Re: Splitting Vector into smalller sub-Vectors

Allan Bruce wrote:
> Boudewijn Dijkstra wrote:
>> "Allan Bruce" <amb@xxxxxxx> schreef in bericht
>> news:KJ6dne1FloMoCgjfRVnytg@xxxxxxxxxxxx
>>
>>> Is it possible to efficiently split a large Vector into smaller
>>> sub-Vectors without iterating through it and adding the Objects to
>>> the sub-Vectors? If not, is there a collection which allows this?
>>> I dont need random access, I am just adding blindly to a single
>>> collection, then want to split it up at the end.
>>
>>
>> java.util.List#subList(int,int)
>>
>>
>
> I tried using ArrayList for this but I get a ClassCastException error
> at the following line:
>
> lArray[j] = (ArrayList)lStates.subList(lStart, lEnd);
>
> What can I do to avoid this? I read the docs but cant see anything
> that says what to do.
>
> Thanks.
> Allan

sublist doesn't split the list. It only provides a view of part of the
underlying list. It does not create a new object. You can't cast it the way
you want because the object that is returned is a RandomAccessSubList, not
an ArrayList.

If you want separate ArrayLists to be created, use

lArray[j] = new ArrayList(lStates.subList(lStart, lEnd));

Which takes the List (or RandamAccessSubList) object from sublist and uses
it to create a new ArrayList.

--
Virgil


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