Bubble Sort

package iteration;

public interface Iterable {
    public Iterator iterator();
}

package dataStructures;

import iteration.Iterable;

public interface List extends Iterable {
    public void insert(int index, Object value)
            throws IndexOutOfBoundsException;
    public void add(Object value);
    public Object delete(int index) throws IndexOutOfBoundsException;
    public boolean delete(Object value);
    public void clear();
    public Object set(int index, Object value)
            throws IndexOutOfBoundsException;
    public Object get(int index) throws IndexOutOfBoundsException;
    public int indexOf(Object value);
    public boolean contains(Object value);
    public int size();
    public boolean isEmpty();
}

package sorting;

import dataStructures.List;

public interface ListSorter {
    public List sort(List list);
}

package sorting;

import dataStructures.List;

public class BubblesortListSorter implements ListSorter {
    private final Comparator _comparator;

    public BubblesortListSorter(Comparator comparator) {
        assert comparator != null : "Comparator cannot be null";
        _comparator = comparator;
    }

    public List sort(List list) {
        assert list != null : "list cannot be null";
        int size = list.size();
        for (int pass = 1; pass < size; ++pass) {
            for (int left = 0; left < (size - pass); ++left) { // inner loop
                int right = left + 1;
                if (_comparator.compare(list.get(left), list.get(right)) > 0) {
                    swap(list, left, right);
                }
            }
        }
        return list;
    }

    private void swap(List list, int left, int right) {
        Object temp = list.get(left);
        list.set(left, list.get(right));
        list.set(right, temp);
    }
}