java - 实现重写 toString 方法的继承

Question

我创建了一个(人、学生、雇员、教职员工)类。 Person 必须对 Student 和 Employee 进行子类化。Employee 有两个子类:Faculty 和 Staff。我已经完成了所有编码，它们工作正常，除了我的驱动程序类 TestPerson 程序 它给出了编译错误

注意:创建 Person、Student、Employee、Faculty、Staff 并调用其 toString 方法的测试程序。

驱动类TestPerson.java的错误如下:-

 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)"

**I am just providing the codes of the driver class. If you need my other codings of the other classes, please state in the comment, and I will immediately post it.

Please see my codings below:-

public class TestPerson {

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

        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");
        }
}

//人员类别

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(class)

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();
    }

}

//员工类

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();
    }
}

//师资类(class)

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();
    }
}

//员工等级

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

您收到这些错误的原因是构造函数不存在。

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

这意味着您将无法编译代码，除非您拥有以下内容:

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

假设您已在构造函数中设置属性，toString 将如下所示:

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

}

更新

你的问题是 Student 只有这个构造函数:

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

Student 需要一个仅使用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您指定的五个参数。