Priority Queue

package dataStructures;

public interface Queue {
    public void enqueue(Object value);
    public Object dequeue() throws EmptyQueueException;
    public void clear();
    public int size();
    public boolean isEmpty();
}

package sorting;

public interface Comparator {
    public int compare(Object left, Object right);
}

package dataStructures;

import sorting.Comparator;

public class SortedListPriorityQueue implements Queue {
    private final List _list;
    private final Comparator _comparator;

    public SortedListPriorityQueue(Comparator comparator) {
        assert comparator != null : "comparator cannot be null";
        _comparator = comparator;_list = new LinkedList();
    }

    public void enqueue(Object value) {
        int pos = _list.size();
        while (pos > 0 && _comparator.compare(_list.get(pos - 1), value) > 0) {
            --pos;
        }
        _list.insert(pos, value);
    }

    public Object dequeue() throws EmptyQueueException {
        if (isEmpty()) {
            throw new EmptyQueueException();
        }
        return _list.delete(_list.size() - 1);
    }

    public void clear() {
        _list.clear();
    }

    public int size() {
        return _list.size();
    }

    public boolean isEmpty() {
        return _list.isEmpty();
    }
}