实现继承重写toString方法

Question

我创建了一个（个人、学生、员工、教职员工）类。Person必须将Student和Employee分为子类。Employee有两个子类：教员和职员。我已经完成了所有的编码，他们工作得很好，除了我的驱动程序类TestPerson程序给出了编译错误

注：一个测试程序，创建一个人、学生、员工、教职员工，并调用他们的toString方法。

驱动程序类TestPerson的错误。以下是java：-

 
error: constructor Student in class Student cannot be applied to given types;
error: no suitable constructor found for Employee(String,String,String,String)
error: constructor Faculty in class Faculty cannot be applied to given types;
error: no suitable constructor found for Staff(String,String,String,String)"

**我只是提供驾驶员等级的代码。如果你需要我对其他课程的其他编码，请在评论中说明，我会立即发布。

请看下面我的代码：-

public class TestPerson {

    public static void main(String[] args) {
        Person person = new Person("John Doe", "123 Somewhere", "415-555-1212", "[e-mail]");
        Person student = new Student("Mary Jane", "555 School Street", "650-555-1212", "[e-mail]", "junior");
        Person employee = new Employee("Tom Jones", "777 B Street", "40-88-889-999", "[e-mail]");
        Person faculty = new Faculty("Jill Johnson", "999 Park Ave", "92-52-22-3-333", "[e-mail]");
        Person staff = new Staff("Jack Box", "21 Jump Street", "707-21-2112", "[e-mail]");

        System.out.println(person.toString() + "\n");
        System.out.println(student.toString() + "\n");
        System.out.println(employee.toString() + "\n");
        System.out.println(faculty.toString() + "\n");
        System.out.println(staff.toString() + "\n");
        }
}

//个人类

public class Person {

    private String name;
    private String address;
    private String phone_number;
    private String email_address;

    public Person() {
    }

    public Person(String newName, String newAddress, String newPhone_number, String newEmail){
        name = newName;
        address = newAddress;
        phone_number = newPhone_number;
        email_address = newEmail;
    }

    public void setName(String newName){
        name = newName;
    }

    public String getName(){
        return name;
    }

    public void setAddress(String newAddress){
        address = newAddress;
    }

    public String getAddress(){
        return address;
    }

    public void setPhone(String newPhone_number){
        phone_number = newPhone_number;
    }

    public String getPhone(){
        return phone_number;
    }

    public void setEmail(String newEmail){
        email_address = newEmail;
    }

    public String getEmail(){
        return email_address;
    }

    public String toString(){
        return "Name :"+getName();
    }

}

//学生类

public class Student extends Person {

    public final String class_status;

    public Student(String name, String address, int phone, String email, String classStatus) {
    super(name, address, phone, email);
    class_status = classStatus;
    }
    public String toString(){
        return "Student Status: " + super.getName();
    }

}

//雇员阶级

import java.util.Date;
public class Employee extends Person{

    private String office;
    private double salary;
    private Date hire;

    public Employee() {
    }

    public Employee(String name, String address, int phone, String email){
        super(name, address, phone, email);
    }

    public Employee(String office, double salary, Date hire){
        this.office = office;
        this.salary = salary;
        this.hire = hire;
    }

    public void setOffice(String office){
        this.office = office;
    }

    public String getOffice(){
        return this.office;
    }

    public void setSalary(double salary){
        this.salary = salary;
    }

    public double getSalary(){
        return this.salary;
    }

    public void setHire(Date hire){
        this.hire = hire;
    }

    public Date getHire(){
        return this.hire;
    }

    public String toString(){
        return "Office " + super.getName();
    }
}

//教师班

public class Faculty extends Employee {
    private String officeHours;
    private int rank;

    public Faculty(String name, String address, int phone, String email) {
    super(name, address, phone, email);
    }

    public String toString(){
        return "Office " + super.getOffice();
    }
}

//职员班

public class Staff extends Employee {
    private String title;

    public Staff(String name, String address, int phone, String email) {
    super(name, address, phone, email);
    }

    public Staff(String title){
        this.title = title;
    }

    public void setTitle(String title){
        this.title = title;
    }
    public String getTitle(){
        return this.title;
    }

    public String toString(){
        return "Title :" + super.getName();
    }
}

Answer 1

Person的构造函数需要一个字符串作为第三个参数，但您正试图将int phone传递给子类中的超级构造函数。那不行，因为型号不对。

顺便说一下：你应该总是用字符串来表示电话号码，而不是整数。

1. 加或减电话号码没有意义。
2. 整数不允许前导零，在一些国家，前导零用于区号。
3. 整数不能大于2147483648，当你试图存储很长的电话号码时，这个看似任意的限制会引起非常意外的bug。

Answer 2

这可能与问题本身无关，但我认为设计可以这样改进：

• 用角色的名字定义抽象类Role
• 定义类学生，员工，员工无论什么继承角色
• 定义类Person，该类具有所有人类型，名称等的公共属性，并且具有角色类型的属性

然后定义toString on Person和all Role实现

通过这种方式，您将能够独立于角色扩展或修改人员，从而使设计更加灵活

Answer 3

出现这些错误的原因是构造函数不存在。

错误：类Student中的构造函数Student不能应用于给定类型；错误：找不到适合员工的构造函数（String，String，String，String）

这意味着您将无法编译代码，除非：

Student(String name, String addr, String phone, String email) {
    ....
}

假设您已经在构造函数中设置了属性，toString将如下所示：

public String toString() {
    return this.name + "\n" + this.addr + "\n" + this.phone + "\n" + this.email;

}

使现代化

你的问题是学生只有这个构造函数：

public Student(String name, String address, int phone, String email, String classStatus)

Student需要一个只接受四个字符串作为参数的构造函数。或者，您可以使所有内容都采用指定的五个参数。