比较具有涉及布尔值的多个属性的列表

Question

我有一些 classes 实现比较器接口以通过添加患者对象对 ArrayList 进行排序，我想按多个属性对列表进行排序并且仅使用枚举进行排序没有问题，但是我想通过用布尔值排序来覆盖这种排序。我知道我不能使用 compareTo 方法，因为它不是 Wrapper class，但我无法找到合适的方法来通过 boolean 对列表进行排序。

如有任何帮助，我们将不胜感激。

    public Patient(int nhsNumber, String name, Status triage, boolean previouslyInQueue, boolean waitingTime){
    this.nhsNumber = nhsNumber;
    this.name = name;
    this.triage = triage;
    this.previouslyInQueue = previouslyInQueue;
    this.waitingTime = waitingTime;

}

这是我的比较器class

public class PatientInQueueComparator implements Comparator<Patient> {

@Override
public int compare(Patient p1, Patient p2) {

    if(p1.isPreviouslyInQueue() && !p2.isPreviouslyInQueue()){
        return 1;
        }else if(p1.isPreviouslyInQueue() && p2.isPreviouslyInQueue()){
        return -1;
        }
        return 0;
}

我的主要方法

List<Patient> queue = new ArrayList<Patient>();

queue.add(new Patient(1, "Bob", Status.URGENT, true, false)); //1st
queue.add(new Patient(2, "John", Status.EMERGENCY, false, false)); //5th
queue.add(new Patient(3, "Mary", Status.NON_URGENT, false, false)); //6th
queue.add(new Patient(4, "Luke", Status.SEMI_URGENT, false, true)); //4th
queue.add(new Patient(5, "Harry", Status.NON_URGENT, true, false)); //2nd
queue.add(new Patient(6, "Mark", Status.URGENT, false, true)); //3rd


System.out.println("*** Before sorting:");

for (Patient p1 : queue) {
    System.out.println(p1);
}

Collections.sort(queue, new PatientComparator( 
        new PatientInQueueComparator(),
        new PatientTriageComparator())
);

System.out.println("\n\n*** After sorting:");

for (Patient p1 : queue) {
    System.out.println(p1);
}

患者比较器

    private List<Comparator<Patient>> listComparators;

 @SafeVarargs
    public PatientComparator(Comparator<Patient>... comparators) {
        this.listComparators = Arrays.asList(comparators);
    }

@Override
public int compare(Patient p1, Patient p2) {
    for (Comparator<Patient> comparator : listComparators) {
        int result = comparator.compare(p1, p2);
        if (result != 0) {
            return result;
        }
    }
    return 0;
}

Answer 1

您只需在 compare 方法中实现适当的逻辑。

@Override
public int compare(Patient p1, Patient p2) {

    if(p1.isPreviouslyInQueue() && !p2.isPreviouslyInQueue()){
        return 1;
        }else if(p1.isPreviouslyInQueue() && p2.isPreviouslyInQueue()){
        return -1;
        }
        //instead of returning zero here, sort by your next criteria
   }

Answer 2

如果您希望 true 值大于 false，您必须更正你的 compare() 方法：

@Override
public int compare(Patient p1, Patient p2) {

    if (p1.isPreviouslyInQueue() && !p2.isPreviouslyInQueue()) 
        return -1;
    if (!p1.isPreviouslyInQueue() && p2.isPreviouslyInQueue()) 
        return 1;
    return 0;
}

通知第二个if。另一个实现可能是：

@Override
public int compare(Patient p1, Patient p2) {
    return ((Boolean)p2.isPreviouslyInQueue()).compareTo(p1.isPreviouslyInQueue());
}

比较具有涉及布尔值的多个属性的列表

compare list with multiple attributes involving a boolean

java

sorting

boolean

linked-list

comparator