incompatible types: required int found object error in generic linkedlist

I am writing a radix sort algorithm (that ONLY sorts integer) and have run into a problem, which could possibly be an easy fix, I just can't seem to find it.

I create and array of linked lists here to hold my integers:

LinkedList[] buckets = {new LinkedList<Integer>(), new LinkedList<Integer>(), new LinkedList<Integer>(), new LinkedList<Integer>(), new LinkedList<Integer>(), new LinkedList<Integer>(), new LinkedList<Integer>(), new LinkedList<Integer>(), new LinkedList<Integer>(), new LinkedList<Integer>()};

That is the generic linkedlist from the util and I only need it to hold integers. My problem is when I try to run this code

            for (int j = 0; j < buckets.length; j++) {
            while (!buckets[j].isEmpty()) {
                a[pos] = buckets[j].removeFirst();
 开发者_Go百科               pos++;
            }

On the line where I remove from my "queue" I get the required int found object error. My linkedlists are hold Integers anyway so why does it say that it is an object? Do I have to downcast somewhere or something along those lines?

Thanks.

Look at your declaration:

LinkedList[] buckets

You've declared an array of raw LinkedList references. You would need to tell the compiler that they'll be LinkedList<Integer> values:

LinkedList<Integer> buckets = ...;

Unfortunately, arrays and generics don't play terribly nicely together. I suggest you use a List<LinkedList<Integer>>, like this:

List<LinkedList<Integer>> buckets = new ArrayList<LinkedList<Integer>>();

for (int i = 0; i < 10; i++)
{
    buckets.add(new LinkedList<Integer>());
}

Then:

for (LinkedList<Integer> bucket : buckets)
{
    while (!bucket.isEmpty())
    {
        a[pos] = bucket.removeFirst();
        pos++;
    }
}