java - 对象的序列化给出了不同的实例？

Question

所以我有 3 个不同的对象:牙医、患者和预约。

牙医和患者各有一个 ArrayList，以便他们共享相同的预约。但问题来了。当我将牙医和患者序列化为文本文件，然后再次反序列化它们时，在预约中所做的更改仅在患者预约中更新？

我有以下创建约会的代码:

Appointment a = new Appointment (p, d, 20.0, startDate, endDate, s);
p.addAppointment(a);
d.addAppointment(a);

patients.add(p);
dentists.add(d);

ReadAndWrite.writePatients(patients, "patients.txt");
ReadAndWrite.writeDentists(dentists, "dentists.txt");

这是同一个奇怪的 Appointment 对象 - 为什么所做的更改在两者中都没有更新？？？

编辑:我在下面添加了 3 个类(以及患者和牙医继承的用户类:

用户:

public class User implements Serializable {

protected String firstName;
protected String lastName;
protected String address;
protected LocalDate dateOfBirth;
protected int phoneNumber;
protected long cpr;
protected int postCode;
protected String username;
protected String password;
protected boolean loggedIn;

protected ArrayList<Appointment> appointments = new ArrayList<Appointment>();

public User (String firstName, String lastName, String address, LocalDate dateOfBirth, int phoneNumber, int cpr, int postCode)
{
    this.firstName = firstName;
    this.lastName = lastName;
    this.address = address;
    this.dateOfBirth = dateOfBirth;
    this.phoneNumber = phoneNumber;
    this.cpr = cpr;
    this.postCode = postCode;


    this.username = createUsername(firstName, lastName);
    this.password = createPassword(lastName, cpr);      
}

public User ()  {   }   

public static String createUsername(String firstName, String lastName) 
{
    if(!(firstName.length() == 0 || lastName.length() < 3))
    {
        String first = firstName.substring(0, 1);
        String last = lastName.substring(0, 3);
        return first + last;
    }       
    return null;
}

public static String createPassword(String lastName, long l) 
{
    if(!(lastName.length() < 3))
    {
        String last = lastName.substring(0 , 3);
        String pass = Long.toString(l);

        pass = pass.substring(pass.length() - 4, pass.length());
        return last + pass;
    }
    return null;
}

public static boolean isPostCodeValid(String s) 
{
    String n = ".*[0-9].*";
    if(s.matches(n) && s.length() == 4)
    {
        int temp = Integer.parseInt(s);

        if (temp <= 9999)
        {
            return true;
        }

        return false;
    }

    return false;
}

public static boolean isCPRValid(String s) 
{
    if (!s.contains("-"))
    {
        return false;
    }

    String[] parts = s.split("-");
    String ddmmyy = parts[0]; 
    String security = parts[1]; 

    if (!(ddmmyy.length() != 6 || security.length() != 4))
    {
        String n = ".*[0-9].*";
        if(ddmmyy.matches(n) && security.matches(n))
        {
            return true;
        }
    }
    return false;
}

public static boolean isPhoneNumberValid(String s) 
{
    if (s.length() != 8)
    {
        return false;
    }
    String n = ".*[0-9].*";
    return (s.matches(n));
}

public static boolean isNameValid(String s) 
{
    if(s.isEmpty())
    {
        return false;
    }
    String n = ".*[0-9].*";
    return !(s.matches(n));
}

public String getFirstName() {
    return firstName;
}

public void setFirstName(String firstName) {
    this.firstName = firstName;
}

public String getLastName() {
    return lastName;
}

public void setLastName(String lastName) {
    this.lastName = lastName;
}

public String getAddress() {
    return address;
}

public void setAddress(String address) {
    this.address = address;
}

public LocalDate getDateOfBirth() {
    return dateOfBirth;
}

public void setDateOfBirth(LocalDate dateOfBirth) {
    this.dateOfBirth = dateOfBirth;
}

public int getPhoneNumber() {
    return phoneNumber;
}

public void setPhoneNumber(int phoneNumber) {
    this.phoneNumber = phoneNumber;
}

public long getCpr() {
    return cpr;
}

public void setCpr(Long cpr) {
    this.cpr = cpr;
}

public int getPostCode() {
    return postCode;
}

public void setPostCode(int postCode) {
    this.postCode = postCode;
}

public String getUsername() {
    return username;
}

public void setUsername(String username) {
    this.username = username;
}

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}

public boolean isLoggedIn() {
    return loggedIn;
}

public void setLoggedIn(boolean loggedIn) {
    this.loggedIn = loggedIn;
}

public ArrayList<Appointment> getAppointments() {
    return appointments;
}


public void addAppointment (Appointment a)
{
    appointments.add(a);
}`

牙医

public class Dentist extends User  {        
    static AtomicInteger nextId = new AtomicInteger();
    private int id;
    protected ArrayList<LocalDateTime> availabilities = new ArrayList<LocalDateTime>();
    protected ArrayList<Service> services = new ArrayList<Service>();
    protected String clinicName;        

    public Dentist(String firstName, String lastName, String address, LocalDate dateOfBirth, int phoneNumber, int cpr, int postCode, String clinicName) {
        super(firstName, lastName, address, dateOfBirth, phoneNumber, cpr, postCode);
        this.clinicName = clinicName;
        id = nextId.incrementAndGet();
    }

    public Dentist()
    {
        id = nextId.incrementAndGet();
    }

    public int getId() {
        return id;
    }

    public ArrayList<LocalDateTime> getAvailabilities() {
        return availabilities;
    }

    public void setAvailabilities(ArrayList<LocalDateTime> availabilities) {
        this.availabilities = availabilities;
    }

    public void addAvailabilities(LocalDateTime date)
    {
        this.availabilities.add(date);
    }

    public ArrayList<Service> getServices() {
        return services;
    }

    public void setServices(ArrayList<Service> services) {
        this.services = services;
    }

    public void addService (Service s)
    {
        services.add(s);
    }

    public String getClinicName() {
        return clinicName;
    }

    public void setClinicName(String clinicName) {
        this.clinicName = clinicName;
    }

    public static void setNextId(AtomicInteger nextId) {
        Dentist.nextId = nextId;
    }

患者:

public class Patient extends User  {

static AtomicInteger nextId = new AtomicInteger();
private int id;
private CreditCard creditCard;

public Patient(String firstName, String lastName, String address, LocalDate dateOfBirth, int phoneNumber, int cpr, int postCode) {
    super(firstName, lastName, address, dateOfBirth, phoneNumber, cpr, postCode);
    this.creditCard = null;
    id = nextId.incrementAndGet();

}

public Patient ()
{
    id = nextId.incrementAndGet();
}

public CreditCard getCreditCard() {
    return creditCard;
}

public void setCreditCard(CreditCard creditCard) {
    this.creditCard = creditCard;
}

public int getId() {
    return id;
}

public static void setNextId(AtomicInteger nextId) {
    Patient.nextId = nextId;
}

预约:

public class Appointment implements Serializable {
private double price;

private Patient patient;
private Dentist dentist;
private Service service;

private LocalDateTime startTime;
private LocalDateTime endTime;

static AtomicInteger nextId = new AtomicInteger();
private int id;

public Appointment(Patient patient, Dentist dentist, double price, LocalDateTime startTime, LocalDateTime endTime, Service service)
{
    this.patient = patient;
    this.dentist = dentist;
    this.price = price;
    this.startTime = startTime;
    this.endTime = endTime;
    this.service = service;
    id = nextId.incrementAndGet();
}

public Appointment()
{
    id = nextId.incrementAndGet();
}

public double getPrice() {
    return price;
}

public void setPrice(double price) {
    this.price = price;
}


public Patient getPatient() {
    return patient;
}

public void setPatient(Patient patient) {
    this.patient = patient;
}

public Dentist getDentist() {
    return dentist;
}

public void setDentist(Dentist dentist) {
    this.dentist = dentist;
}

public LocalDateTime getStartTime() {
    return startTime;
}

public void setStartTime(LocalDateTime startTime) {
    this.startTime = startTime;
}

public LocalDateTime getEndTime() {
    return endTime;
}

public void setEndTime(LocalDateTime endTime) {
    this.endTime = endTime;
}

public int getId() {
    return id;
}


public String toString()
{
    return getService().getName() + " -------" + "aID: " + getId() + "   " + getStartTime() + " with PATIENT: " + patient.getFirstName() +" " + patient.getLastName() + " and DENTIST: " + dentist.getFirstName() + " " + dentist.getLastName() + " at " + dentist.getAddress();
}

public Service getService() {
    return service;
}

public void setService(Service service) {
    this.service = service;
}

public static void setNextId(AtomicInteger nextId) {
    Appointment.nextId = nextId;
}

序列化代码:

public static void writePatients(ArrayList<Patient> list, String file) 
{
    try {
        FileOutputStream f = new FileOutputStream(new File(file));
        ObjectOutputStream o = new ObjectOutputStream(f);
        o.writeObject(list);            
        o.close();
        f.close();                      
    } catch (FileNotFoundException e) {
        System.out.println("File not found");
    } catch (IOException e) {
        System.out.println("Error initializing stream");
    }
}

Answer 1

您必须更改您的实现，以便一次对所有对象进行(反)序列化。例如通过提供/实现

public class PersistenceService {
  public void serialize(String fname, List<Serializable> outgoing) {...

  public List<Serializable> deserialize(String fname) {

您已经拥有实现此类的大部分代码；最重要的是，您只需:

• 将您的列表“合并”为一个以便写作
• 检索该单个列表；并根据每个条目的特定类别将其“切片”为子列表(例如，通过迭代该结果列表；并使用 instanceof 来确定每个条目是否是患者、牙医等...... .)