如何使用比较器对重复的字符串进行排序？

Question

假设我有一个包含工人的列表,每个工人有3个字段:它的名称,他所在的部门(可以只是部门的名称或班级部门的对象)和他的工资.

Elvis       Software Engineering        1000
Samba       Mechanical Engineering      2000
Bamba       Industrial Engineering      3000
Bisli       Medical Engineering         4000
Kinder      Electrical Engineering      1000
Elvis       Software Engineering        9999

现在我想按名字对它们进行排序,并将结果放入队列中.然后将队列放在地图中,从底部到顶部排序,以便排序后我想要的结果是:

Bamba       Industrial Engineering      3000
Bisli       Medical Engineering         4000
Elvis       Software Engineering        1000
Elvis       Software Engineering        9999
Samba       Mechanical Engineering      2000
Kinder      Electrical Engineering      1000

我不允许使用Collection.sort(),因此我使用比较器按名称对工人进行排序,如果名称相同 - 按部门排序,如果部门相同 - 按类别排序薪水.这是我写的比较器:

    class WorkerComparatorByName implements Comparator<Worker<?>> {
    @Override
    public int compare(Worker<?> w1, Worker<?> w2) {
        int compareValue = w1.getName().compareTo(w2.getName());
        if (compareValue != 0)
            return compareValue;
        compareValue = w1.getDepartment().toString().compareTo(w2.getDepartment().toString());
        if (compareValue != 0)
            return compareValue;
        return w1.getSalary() - w2.getSalary();

    }
}

问题是结果如下:

Bamba       Industrial Engineering      3000
Bisli       Medical Engineering         4000
Elvis       Software Engineering        1000
Samba       Mechanical Engineering      2000
Kinder      Electrical Engineering      1000
Elvis       Software Engineering        9999

所有工作人员都被排序,但是Elvis(重复的)没有排序,它停留在队列的末尾.我尝试用另一个重复的名称替换Elvis,结果相同.我错过了什么？我怎样才能对重复值进行排序,以便它们一个接一个？这是代码:

    public <T extends Worker<?>> Map<?, ?> createMap(ArrayList<T> list) {
    int i = 1;
    // creating a PriorityQueue sorted by names
    Queue<T> pq = new PriorityQueue<>(new WorkerComparatorByName());
    // filling the PriorityQueue with the workers
    pq.addAll(list);
    Map<Integer, T> treeMap = new TreeMap<Integer, T>();
    // iterating over the PriorityQueue and puting the workers in the map
    for (T element : pq)
        treeMap.put(i++, element);
    return treeMap;
}

Answer 1

优先队列 API：

iterator() 方法中提供的迭代器不保证以任何特定顺序遍历优先级队列的元素。如果需要有序遍历，请考虑使用 Arrays.sort(pq.toArray())。