在尝试使用此泛型类的优先级队列时，是否应使用Comparator或Comparable？

Question

当尝试在优先级队列中为泛型对象赋予优先级时，我可以使用什么来比较它们？我可以从Comparable接口定义并使用重写的CompareTo方法，还是从Comparator接口定义并使用重写的CompareTo方法？或者我可以用一个还是另一个？谢谢

下面是实例变量、类的构造函数和当前的compareTo方法。

private LocalTime scheduledTime; //the scheduled time of the flight
private Event.EventType eventType; //the event type of the flight (arrival or departure)
private String identifier;  // the identifier of the flight
private LocalTime actualTime; //the actual time the flight uses a runway
private Runway runwayUsed; //the runway the flight used to arrive or depart
private int reserveTime; // time the flight uses to reserve a runway 
private LocalTime runwayAvailableTime;


/**
 * Constructor
 * @param scheduledTime the scheduled time of the flight
 * @param eventType the event of the flight (arrival or departure)
 * @param identifier the identifier of the flight
 */
protected Flight(String scheduledTime, String eventType, String identifier) {


    this.scheduledTime = LocalTime.parse(scheduledTime);
    this.eventType = EventType.valueOf(eventType);
    this.identifier = identifier;
    this.actualTime = null;
    this.runwayUsed = null;

} 

//Here is the compareTo method I am currently using. Should I use compare //from the Comparator interface instead?
@Override
public int compareTo(Event otherFlight) {

    Event tmpFlight = (Event) otherFlight;


        if(this.scheduledTime.compareTo(tempFlight.getScheduledTime()) == 0) {
        if(this.eventType.compareTo(tempFlight.getEvent()) == 0){
            return 0;
        } 
        else if(this.eventType.compareTo(tempFlight.getEvent()) > 0){
            return 1;
        } 
        else {
            return -1;
        } 
    } 
    else if(this.scheduledTime.compareTo(tempFlight.getScheduledTime()) < 0) {
        return -1;
    } 
    else {
        return 1;
    }  }

Answer 1

因为您已经实现了compareTo，所以您有可比Flight或事件实例。

这意味着您已将其设置为与可比较的对象一起使用。以下所有操作都应有效：

Queue<Event> eventQueue = new PriorityQueue<>();
eventQueue.add(new Flight(scheduledTime, eventType, identifier));

或：

List<Flight> flightList = Arrays.asList(new Flight(scheduledTime, 
                           eventType, identifier));
Queue<Flight> flightQueue = new PriorityQueue<>(flightList);

或：

List<Event> eventList = ...;
Queue<Event> eventQueue = new PriorityQueue<>(eventList);

PiorityQueue类应该能够根据您的compareTo排序所指定的顺序来处理优先级。

注意：如果您的列表