java - PriorityQueue 顺序不正确 JAVA

Question

我确实有一个实现 Comparable 的 User 类。在我将用户列表添加到 PriorityQueue<User> 之后，他们应该被 scores 优先考虑，但由于某些原因他们没有。你能帮我弄清楚为什么用户没有在我的 Queue 中排序吗？

更新:

我正在通过轮询元素来访问队列。 prioritisedUsers.poll() 它总是带有随机分数并尊重顺序。

PriorityQueue<User> prioritisedUsers = userPriorityStrategy.computeUserPriority(users);

while(!prioritisedUsers.isEmpty()){
    System.out.println(prioritisedUsers.poll().getPriorityScore());
}

输出:

0.35036433736768735
0.6619121139678329
0.09520067929838127
0.4013591573863
0.6704568389588227
0.5989900926939181
0.7320779721160738

感谢您的帮助!

public class User implements Comparable<User>{

    private long id;
    private String fistName;
    private String lastName;
    private double priorityScore;

    public User (long id, String firstName, String lastName){
        this.id = id;
        this.fistName = firstName;
        this.lastName = lastName;
    }

    public double getPriorityScore(){
        return this.priorityScore;
    }

    public void setPriorityScore(double priorityScore){
        this.priorityScore = priorityScore;
    }

    public long getId(){
        return this.id;
    }

    public String getFistName(){
        return this.fistName;
    }

    public String getLastName(){
        return this.lastName;
    }

    public int compareTo(User o) {
        return (int) (this.getPriorityScore() - o.getPriorityScore());
    }
}


    public PriorityQueue<User> computeUserPriority(List<User> users) {
        PriorityQueue<User> prioritisedUsers = new PriorityQueue<User>(users.size());
        for (User user : users) {
            user.setPriorityScore(rand.nextDouble());
            prioritisedUsers.add(user);
        }
        return prioritisedUsers;
    }

Answer 1

我不太确定您对 (int) 的转换是否正常...因为转换为 int 会隐式删除任何小数。

如果我没记错的话，试试类似的方法

public int compareTo(User object) {
if (this.getPriorityScore() < object.getPriorityScore())
    return -1;
if (this.getPriorityScore() == object.getPriorityScore())
    return 0;
return 1;
}

或者更简单地:

public int compareTo(User o) {
    return Double.compare(this.getPriorityScore(), o.getPriorityScore());
}