PriorityQueue命令不正確JAVA

Question

我確實有一個User類，它實現了Comparable。在我將用戶列表添加到PriorityQueue<User>之後，他們應該優先選擇scores，但由於某些原因，他們不會。您能否幫我弄清楚爲什麼用戶沒有在我的Queue中排序？

更新：

我正在通過輪詢元素訪問隊列。 prioritisedUsers.poll()它總是隨訂單尊重隨機得分。

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

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

OUTPUT：

0.35036433736768735 
0.6619121139678329 
0.09520067929838127 
0.4013591573863 
0.6704568389588227 
0.5989900926939181 
0.7320779721160738 

感謝您的幫助！

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

我不太確定你的轉換爲（int）的效果不錯......因爲轉換爲int會隱式地丟棄任何小數。

如果我在錯誤的我不是，你可以試試

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

或可選擇地和更簡單：

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