java - 在 Java 中使用 Student 类中的 Address 类和 toString

Question

我正在尝试创建一个程序，您可以在其中添加学生信息及其地址。因此，我创建了 2 个类，Student 类和 Adres 类(荷兰语中的地址)。在 Adres 类中，我有地址数据，在 Student 类中有学生数据。

但是我在为我的 Student 类创建构造函数时遇到了困难，因为当您添加新学生时，还需要添加该学生的地址。

我尝试在 Student 中使用 toString 方法，但也需要返回地址。

所以我有 3 个问题:

1. 如何为 Student 类设置构造函数，其中还需要添加地址
2. 如何设置 toString 方法，该方法还从 Adres 返回“toString”。
3. 添加新学生时如何输入本地日期和地址。 (本地日期用于学生生日)

我对 java 还很陌生，如果有人能帮助我那就太好了。

我的地址类:

package oop3.studenten;

public class Adres {

    private String straat;
    private Integer huisnr;
    private String postcode;
    private String plaats;

    public Adres(String straat, Integer huisnr, String postcode, String plaats) {
        this.straat = straat;
        this.huisnr = huisnr;
        this.postcode = postcode;
        this.plaats = plaats;
    }


    public String toString() {
        return straat + "" + huisnr + "," + postcode + "" + plaats;
    }




    // Using regex to check if postcode is valid
    public static boolean checkPostcode(String postCode) {
        return postCode.matches("[1-9][0-9]{3}[a-zA-Z]{2}");
    }


}

我的学生类(class):

package oop3.studenten;

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;

public class Student {

    private Integer studentnr; //StudentId
    private String voornaam; //Firstname
    private String achternaam; //Lastname
    private LocalDate geboortedatum; //Birthday
    private Adres adres; //address 

    // constructor for Student
    public Student(Integer studentnr, String voornaam, String achternaam, LocalDate geboortedatum, Adres adres){
        this.studentnr = studentnr;
        this.voornaam = voornaam;
        this.achternaam = achternaam;
        this.geboortedatum = geboortedatum;
        this.adres = new Adres(); 
    }

    // toString method for Student
    @Override
    public String toString() {
        return "Student{" +
                "studentnr=" + studentnr +
                ", voornaam='" + voornaam + '\'' +
                ", achternaam='" + achternaam + '\'' +
                ", geboortedatum=" + korteGeboortedatum(geboortedatum) +
                ", adres=" + adres +
                '}';
    }

    // method to return birthday (geboortedatum) in day month year format
    public String korteGeboortedatum(LocalDate gebdatum ){
        return gebdatum.format(DateTimeFormatter.ofPattern("dd-MM-yyyy"));
        }

}

以及我尝试添加学生的主类(class)

package oop3.studenten;


public class Main {

    public static void main(String[] args) {

        Student student = new Student(500739074, "Ronny", "Giezen", 22111997, "?"
        );
    }

}

提前致谢

Answer 1

学生构造函数:

public Student(Integer studentnr, String voornaam, String achternaam, LocalDate geboortedatum, Adres adres){
    this.studentnr = studentnr;
    this.voornaam = voornaam;
    this.achternaam = achternaam;
    this.geboortedatum = geboortedatum;
    this.adres = adres; //if you do "new Adres();" a completely empty adres instance would be created, instead you want to use the one passed as parameter
}

// toString method for Student
@Override
public String toString() {
    return "Student{" +
            "studentnr=" + studentnr +
            ", voornaam='" + voornaam + '\'' +
            ", achternaam='" + achternaam + '\'' +
            ", geboortedatum=" + korteGeboortedatum(geboortedatum) +
            ", adres=" + adres.toString() +
            '}'; //                ^^ calling the .toString()-method of adres and appending it to the rest
}

主类:

public static void main(String[] args) {
    Adres adres = new Adres("Mainstreet", 5, "48484", "Amsterdam"); //creating the adress
    LocalDate birthday = LocalDate.of(2017, 1, 13);                 //creating the birthday-localdate
    Student student = new Student(500739074, "Ronny", "Giezen", birthday, adres); //passing the birthday & adres to the student-constructor
}