我有一个任务,我必须根据紧急情况对患者进行排序,如果他们具有相同的紧急程度,那么它基于到达顺序,但是当我进行排序时,我收到一条错误消息,说“方法sort(集合类型中的列表,比较器)不适用于参数(列表,比较器)“有人可以帮忙吗?以下是我的所有代码:
import java.util.Comparator;
public class Patient implements Comparable<Patient> {
// attributes
private String name;
private int order; // order of arrival
private int emergency; // 1 is normal, 5 is life-and-death situation
// constructor
public Patient(int order, String name, int priority) {
this.order = order;
this.name = name;
this.emergency = priority;
}
// getters and setters
public int getOrder() {
return order;
}
public void setOrder(int order) {
this.order = order;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getEmergency() {
return emergency;
}
public void setEmergency(int emergency) {
this.emergency = emergency;
}
public String toString() {
return name;
}
@Override
public int compareTo(Patient patient) {
// TODO Auto-generated method stub
int total = 0;
if (emergency < patient.emergency) {// compares patient emergency
total = 1;
} else if (emergency == patient.emergency) {
if (order < patient.order) {// compares order of arrival in case emergencies are the same
total = -1;
} else if (order > patient.order) {
total = 1;
}
} else if (emergency > patient.emergency) {
total = -1;
}
return total;
}
public static class Comparators {
public static final Comparator<Patient> EMERGENCY = (Patient p1, Patient p2) -> Integer.compare(p1.getEmergency(), p2.getEmergency());
public static final Comparator<Patient> ORDER = (Patient p1, Patient p2) -> Integer.compare(p1.getOrder(), p2.getOrder());
}}
import java.util.*;
public class PatientManager{
private PriorityQueue<Patient> waitingList;
public PatientManager() {
waitingList = new PriorityQueue<Patient>();
}
// Starter method
public void start() {
String choice;
Scanner in = new Scanner(System.in);
String name;
int emergency = 0;
int order = 0;
List<Object> list = null;
Patient patient;
System.out.println("-------------------------------");
System.out.println("(1) New Patient.");
System.out.println("(2) Next Patient.");
System.out.println("(3) Waiting List.");
System.out.println("(4) Exit.");
System.out.println("-------------------------------");
while (true) {
//clear screen
System.out.print("* Choose an item from the menu: ");
choice = in.next();
switch (choice) {
case "1":
System.out.print("Enter patient's name: ");
name = in.next();
System.out.print("Enter emergency [1 (low) to 5 (life-and-death)]: ");
while (emergency < 1 || emergency > 5) {//testing for emergency and if any wrong values are given clears the scanner and tries again
try {
emergency = in.nextInt();
if (emergency < 1 || emergency > 5)
System.out.print("(x) Wrong value. Try again: ");
}
catch (Exception e) {
System.out.print("(x) Wrong value. Try again: ");
in.next();
}
}
order++;//Sets the number of the arrival.
patient = new Patient(order, name, emergency);
waitingList.add(patient);
System.out.println("Patient added to the waiting list.");
emergency = 0;//resetting value of emergency otherwise all patients will have the same one and loop will not run a second time
Arrays.sort(waitingList.toArray());
break;
case "2":
if (waitingList.isEmpty()) {
System.out.println("No more patients.");
} else {
patient = waitingList.remove();
System.out.println(patient.getName() + " is treated.");
}
break;
case "3":
if (waitingList.size() == 0) {
System.out.println("No patients in the list.");
} else {
System.out.println("Waiting list includes:");
list = new ArrayList<Object>(waitingList);
Collections.sort(list, Patient.Comparators.EMERGENCY);
for (int i=0;i<waitingList.size();i++) {
System.out.println("- " + list.get(i));
}
}
break;
case "4":
System.out.println("Program terminated. Good bye!!");
in.close();
System.exit(0);
break;
// print list name and emergency
default:
System.out.println("(x) Wrong choice.");
break;
}
}
}}
最佳答案
问题是要排序的列表已声明为可以包含任意对象的列表。您不能将“患者”的比较器应用于可能不是“患者”的对象。
要解决此问题,请将您的列表声明为患者列表:
List<Patient> list = new ArrayList<>(waitingList)
关于java - 尝试解决“Collections类型中的方法sort(List <T>,Comparator <?super T>)对参数不适用”,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/60906955/