Fast array list eraser

import java.util.ArrayList;

/**
 * @author: GeneralGDA
 * @since: 19.02.2009; 21:53:50
 */
public final class ArrayListCleaner
{
    private ArrayListCleaner()
    {
        throw new UnsupportedOperationException();
    }

    /**
     * Algorithm: check element. If it expired - move to it's position
     * element from containers' end.
     *
     * @param list list to clear of invalid elements.
     * @param validator invalid object detector.
     * @return true if at least one object was deleted.
     */
    public static <T> boolean removeInvalidObjects(final ArrayList<T> list, final Validator<T> validator)
    {
        if (null == list || list.isEmpty() || null == validator)
        {
            return false;
        }

        boolean atLeastOneBadFound = false;

        int lastIndex = list.size() - 1;
        for (int i = 0; i < lastIndex; i++)
        {
            final T element = list.get(i);
            if (validator.process(element))
            {
                atLeastOneBadFound = true;
                list.set(i, list.get(lastIndex));
                list.remove(lastIndex);
                lastIndex--;
                i--;
            }
        }

        final T element = list.get(lastIndex);
        if (validator.process(element))
        {
            atLeastOneBadFound = true;
            list.remove(lastIndex);
        }

        return atLeastOneBadFound;
    }
}