Java ArrayList removeAll

Question

我正在研究一个虚拟医院数据库。我有一个ArrayList，它结合了医生理论上可以预约的所有可能时间，还有一个ArrayList，它持有实际的注册预约。

Availability {
  int doctorid;
  String specialty;
  Date date;
  int order_of_appointment;
}
//////////

ArrayList<Availability> allTimes;

ArrayList<Availability> busyTimes;

我想要完成的是找到医生空闲的时间。这是 (allTimes - busyTimes) 的结果

我尝试使用allTimes.removeAll(busyTimes)，但没有删除任何内容。

我确保我覆盖了 Availability 类中的 equals() 方法，但它仍然没有删除任何内容。

@Override
public boolean equals(Object o) {
  if (this == o) return true;
  if (!(o instanceof Availability)) return false;   
  Availability that = (Availability) o;
  return doctorid == that.doctorid &&
      order_of_appointment == that.order_of_appointment &&
      Objects.equals(specialty, that.specialty) &&
      Objects.equals(date, that.date);
} 

---

输出：

1. busyTimes = [可用性{doctorid=1，专业='内科'，日期=2021-11-02，order_of_appointment=2} ]

2. 所有时间 = [可用性{doctorid=1，专业='内科'，日期=2021-11-02，order_of_appointment=1} , 可用性{doctorid=1, special='内科', date=2021-11-02, order_of_appointment=2} , 可用性{doctorid=1,specialty='内科', date=2021-11-02, order_of_appointment=3}]

3. 我为 freeTimes 获得的输出与 allTimes 相同，尽管我希望它会删除 order_of_appointment==2 的约会。

我完全不知道是什么原因造成的。任何帮助，将不胜感激。提前致谢！

Answer 1

问题在于，即使我将日期格式设置为“yyyy-MM-dd”，它仍然将时间存储在 Date 对象中。我将 Date 对象转换为字符串，然后比较字符串并且工作正常。谢谢大家。

Answer 2

您需要使用比较逻辑覆盖 可用性类 中的 equals(Object obj) 方法。

我实现了它。请检查。

import java.util.Date;

public class Availability {

    private int doctorId;
    private String specialty;
    private Date date;
    private int orderOfAppointment;

    public Availability() {
        super();        
    }

    public Availability(int doctorId, String specialty, Date date, int orderOfAppointment) {
        super();
        this.doctorId = doctorId;
        this.specialty = specialty;
        this.date = date;
        this.orderOfAppointment = orderOfAppointment;
    }

    public int getDoctorId() {
        return doctorId;
    }

    public void setDoctorId(int doctorId) {
        this.doctorId = doctorId;
    }

    public String getSpecialty() {
        return specialty;
    }

    public void setSpecialty(String specialty) {
        this.specialty = specialty;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    public int getOrderOfAppointment() {
        return orderOfAppointment;
    }

    public void setOrderOfAppointment(int orderOfAppointment) {
        this.orderOfAppointment = orderOfAppointment;
    }

    @Override
    public String toString() {
        return "Availability  [doctorId=" + doctorId + ", specialty=" + specialty + ", date=" + date
                + ", orderOfAppointment=" + orderOfAppointment + "]";
    }

    @Override
    public boolean equals(Object obj) {
        boolean returnVal = false;
        Availability busyslote = (Availability) obj;
        if (this.doctorId == busyslote.doctorId && this.orderOfAppointment == busyslote.orderOfAppointment
                && this.specialty.equalsIgnoreCase(busyslote.specialty) && this.date.equals(busyslote.date)) {
            returnVal = true;
        } else {
            returnVal = false;
        }

        return returnVal;
    }
}

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class AppointmentMain {

    public static void main(String[] args) {

        List<Availability> allAppointment = new ArrayList<>();
        List<Availability> attenedAppointment = new ArrayList<>();

        Availability obj1 = new Availability(1, "Internal Medicine", new Date(), 1);
        Availability obj2 = new Availability(1, "Internal Medicine", new Date(), 2);
        Availability obj3 = new Availability(1, "Internal Medicine", new Date(), 3);

        allAppointment.add(obj1);
        allAppointment.add(obj2);
        allAppointment.add(obj3);

        Availability obj4 = new Availability(1, "Internal Medicine", new Date(), 3);

        attenedAppointment.add(obj4);

        System.out.println("Befour count :" + allAppointment.size());
        allAppointment.removeAll(attenedAppointment);
        System.out.println("After count :" + allAppointment.size());
    }
}

Answer 3

你没有展示你是如何创建数组的，或者你是如何添加元素的。

我用 ArrayLists 做了一个简单的程序，并按预期工作：

import java.util.*;

class A {
  int id;
  A(int id) {
    this.id = id;
  }

  @Override
  public boolean equals(Object o) {
    return o instanceof A && this.id == ((A)o).id;
  }
  public String toString() {
    return String.format("A{id:%s}", id);
  }

  public static void main(String ... args) {
    List<A> a = new ArrayList<A>(Arrays.asList(new A(1), new A(2)));
    List<A> b = new ArrayList<A>(Arrays.asList(new A(2), new A(3)));
    a.removeAll(b);
    System.out.println(a);
  }
}

输出：

[A{id:1}]