我试图使用接口比较器来订购一个优先队列,这样如果乘客的订单有残疾,他们的订单就取决于第一个订单,然后取决于他们有的票的类型以及最后的到达时间。如何将Comparator与多个字段对象一起使用?
import java.util.*;
public static void main(String[] args){
Random rand = new Random(System.nanoTime());
Comparator<Passenger> comparator;
PriorityQueue<Passenger> queue = new PriorityQueue<Passenger>(10, comparator);
Passenger pass[] = new Passenger [10];
for (int i=0; i<10;i++){
int time1 = 0;
pass[i] = new Passenger(rand.nextInt(100000000), rand.nextInt(3) , rand.nextBoolean(), time1);
time1 = time1 + 15;
}
}
有我初始化乘客的阵列,这里是头等舱乘客和比较方法:
public class Passenger implements Comparator<Passenger>{
private int ID;
private int clase;
private boolean disability;
private int arrivalTime;
public Passenger(int ID, int clase, boolean disability, int arrivalTime) {
this.ID = ID;
this.clase = clase; // 0-vip 1-economy 2-economy
this.disability = disability;
this.arrivalTime = arrivalTime;
}
public int getID() {
return ID;
}
public void setID(int iD) {
ID = iD;
}
public int getClase() {
return clase;
}
public void setClase(int clase) {
this.clase = clase;
}
public boolean isDisability() {
return disability;
}
public void setDisability(boolean disability) {
this.disability = disability;
}
public int getArrivalTime() {
return arrivalTime;
}
public void setArrivalTime(int arrivalTime) {
this.arrivalTime = arrivalTime;
}
public int compare(Passenger pas1, Passenger pas2) {
if((pas1.isDisability()) && (!pas2.isDisability())){
return 1; //passenger 1 has disability
}else if((!pas1.isDisability()) && (pas2.isDisability())){
return -1; //passenger 2 has disability
}
else{ //both have disability or no one has disability
if(pas1.getClase() < pas2.getClase()){
return 1; // passenger 1 has better class
}else if(pas1.getClase() > pas2.getClase()){
return -1; // passenger 2 has better class
}
else{ //both have disability and same class
if(pas1.getArrivalTime() < pas2.getArrivalTime()){
return 1; //passenger 1 arrived before passenger 2
}
else return -1; //passenger 2 arrived before passenger 1
}
}
}
我该如何处理以更好的方式,这些多层次的比较?
所以具体是什么问题呢?代码是否会抛出错误?它排序不正确吗? – Keiwan
你比较,你通过一个构造函数的参数为空 – Rogue