用Java的代码定义一个person类，包含姓名、性别、年龄等字段；继承person类，设计teacher类，增加：职称、部门等字段；继承person类设计Student类增加，学号、班级等字段，定义各类的构造方法和to String()方法，并分贝创建对象进行测试

好的，以下是用Java代码定义Person、Teacher和Student类的实现，并且包含构造方法和to String()方法：

public class Person {
    private String name;
    private String gender;
    private int age;

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

    public String toString() {
        return "Name: " + name + ", Gender: " + gender + ", Age: " + age;
    }

    // Getters and Setters omitted for brevity
}

public class Teacher extends Person {
    private String position;
    private String department;

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

    public String toString() {
        return super.toString() + ", Position: " + position + ", Department: " + department;
    }

    // Getters and Setters omitted for brevity
}

public class Student extends Person {
    private String studentNumber;
    private String className;

    public Student(String name, String gender, int age, String studentNumber, String className) {
        super(name, gender, age);
        this.studentNumber = studentNumber;
        this.className = className;
    }

    public String toString() {
        return super.toString() + ", Student Number: " + studentNumber + ", Class Name: " + className;
    }

    // Getters and Setters omitted for brevity
}

然后我们可以在main方法中创建Person、Teacher和Student类的对象并进行一些测试，例如：

public static void main(String[] args) {
    Person person = new Person("John Doe", "Male", 25);
    System.out.println(person.toString());

    Teacher teacher = new Teacher("Jane Smith", "Female", 35, "Associate Professor", "Computer Science");
    System.out.println(teacher.toString());

    Student student = new Student("Tom Lee", "Male", 18, "20210001", "Class A");
    System.out.println(student.toString());
}

输出结果如下：

Name: John Doe, Gender: Male, Age: 25
Name: Jane Smith, Gender: Female, Age: 35, Position: Associate Professor, Department: Computer Science
Name: Tom Lee, Gender: Male, Age: 18, Student Number: 20210001, Class Name: Class A