java/W5/Person.java

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

// 公共父类 Person
class Person {
    protected String id;
    protected String name;
    protected int age;

    public Person(String id, String name, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }

    // 公共方法：展示基本信息
    public void showInfo() {
        System.out.println("ID: " + id + ", 姓名: " + name + ", 年龄: " + age);
    }
}

// 子类 Student（学生）
class Student extends Person {
    private String studentNo; // 学号（特有属性）
    private String major;     // 专业（特有属性）

    public Student(String id, String name, int age, String studentNo, String major) {
        super(id, name, age);
        this.studentNo = studentNo;
        this.major = major;
    }

    // 重写 showInfo，展示学生特有信息
    @Override
    public void showInfo() {
        super.showInfo();
        System.out.println("学号: " + studentNo + ", 专业: " + major);
        System.out.println("------------------------");
    }

    // 学生特有方法
    public String getStudentNo() {
        return studentNo;
    }
}

// 子类 Teacher（老师）
class Teacher extends Person {
    private String teacherNo; // 工号（特有属性）
    private String department;// 院系（特有属性）

    public Teacher(String id, String name, int age, String teacherNo, String department) {
        super(id, name, age);
        this.teacherNo = teacherNo;
        this.department = department;
    }

    // 重写 showInfo，展示老师特有信息
    @Override
    public void showInfo() {
        super.showInfo();
        System.out.println("工号: " + teacherNo + ", 院系: " + department);
        System.out.println("------------------------");
    }

    // 老师特有方法
    public String getTeacherNo() {
        return teacherNo;
    }
}

// 管理类：用多态统一管理
class PersonManager {
    private List<Person> personList = new ArrayList<>();

    // 统一添加方法：替代 addStudent 和 addTeacher
    public void addPerson(Person p) {
        // 1. 处理公共属性：直接通过父类引用操作
        System.out.println("正在添加人员: " + p.name);

        // 2. 处理子类特有属性：通过类型判断 + 向下转型
        if (p instanceof Student) {
            Student student = (Student) p;
            System.out.println("学生学号: " + student.getStudentNo() + "，已录入学生信息");
        } else if (p instanceof Teacher) {
            Teacher teacher = (Teacher) p;
            System.out.println("老师工号: " + teacher.getTeacherNo() + "，已录入老师信息");
        }

        // 3. 统一存入集合
        personList.add(p);
        System.out.println("添加成功！\n");
    }

    // 统一展示所有人员信息
    public void showAllPersons() {
        System.out.println("=== 所有人员信息 ===");
        for (Person p : personList) {
            p.showInfo(); // 多态调用：自动匹配子类的 showInfo
        }
    }
}